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Sample records for african plate relative

  1. Plio-Quaternary paleostresses in the Atlantic passive margin of the Moroccan Meseta: Influence of the Central Rif escape tectonics related to Eurasian-African plate convergence

    NASA Astrophysics Data System (ADS)

    Chabli, Ahmed; Chalouan, Ahmed; Akil, Mostapha; Galindo-Zaldívar, Jesús; Ruano, Patricia; Sanz de Galdeano, Carlos; López-Garrido, Angel Carlos; Marín-Lechado, Carlos; Pedrera, Antonio

    2014-07-01

    The Atlantic Moroccan Meseta margin is affected by far field recent tectonic stresses. The basement belongs to the variscan orogen and was deformed by hercynian folding and metamorphism followed by a post-Permian erosional stage, producing the flat paleorelief of the region. Tabular Mesozoic and Mio-Plio-Quaternary deposits locally cover the Meseta, which has undergone recent uplift, while north of Rabat the subsidence continues in the Gharb basin, constituting the foreland basin of the Rif Cordillera. The Plio-Quaternary sedimentary cover of the Moroccan Meseta, mainly formed by aeolian and marine terraces deposits, is affected by brittle deformations (joints and small-scale faults) that evidence that this region - considered up to date as stable - is affected by the far field stresses. Striated faults are recognized in the oldest Plio-Quaternary deposits and show strike-slip and normal kinematics, while joints affect up to the most recent sediments. Paleostress may be sorted into extensional, only affecting Rabat sector, and three main compressive groups deforming whole the region: (1) ENE-WSW to ESE-WNW compression; (2) NNW-SSE to NE-SW compression and (3) NNE-SSW compression. These stresses can be attributed mainly to the NW-SE oriented Eurasian-African plate convergence in the western Mediterranean and the escape toward the SW of the Rif Cordillera. Local paleostress deviations may be related to basement fault reactivation. These new results reveal the tectonic instability during Plio-Quaternary of the Moroccan Meseta margin in contrast to the standard passive margins, generally considered stable.

  2. Polarization Anisotropy Along the Anatolian African Plate Boundary

    NASA Astrophysics Data System (ADS)

    Sandvol, E.; Polat, G.; Lough, A.; Sahin, S.; Turkelli, N.

    2006-12-01

    This study focuses on mantle flow beneath and around the Anatolian plate using measurements of seismic anisotropy. Observations of shear wave splitting across the Anatolian plate have a NE-SW fast direction and lag time similar to that observed from temporary broadband stations within the plate, indicating that the anisotropic fabric may be relatively uniform throughout the upper mantle beneath the Anatolian plate. The extensive young basaltic volcanism, regional travel time tomography, and regional phase attenuation tomography all indicate that the lithospheric mantle beneath most of the Anatolian plate has largely been removed or is very thin. Unless exceptionally high anisotropy exists in the thinned lithosphere, the main contribution to the observed delay times (of order 1 s) must therefore be asthenospheric and thus reflect recent asthenospheric flow patterns. One exception appears to be a change in the fast direction across a region of concentrated extension in western Anatolia. We observe a change in the orientation of the splitting that is consistent with the direction of crustal extension. The African-Anatolian plate boundary is made up of two very different convergent margins: the Hellenic arc to the west and the Cyprian arc to the east. There is substantial evidence that the Hellenic arc is retreating and the Cyprian arc is relatively stationary. Furthermore, both earthquake hypocenters and tomographic models indicate that the Cyprian angle of subduction is much less steep than the subduction occurring along the Hellenic arc. This substantial geometric difference implies that there is a tear or gap in the subduction of African oceanic lithosphere beneath the Anatolian plate along what is called the Isparta Angle. We are investigating mantle dynamics and mantle flow around and through this possible tear in the lithosphere. We will use a combination of seismic tomographic methods (surface wave, body wave, and attenuation) as well as neotectonics studies to

  3. Current plate velocities relative to the hotspots incorporating the NUVEL-1 global plate motion model

    SciTech Connect

    Gripp, A.E.; Gordon, R.G. )

    1990-07-01

    NUVEL-1 is a new global model of current relative plate velocities which differ significantly from those of prior models. Here the authors incorporate NUVEL-1 into HS2-NUVEL1, a new global model of plate velocities relative to the hotspots. HS2-NUVEL1 was determined from the hotspot data and errors used by Minster and Jordan (1978) to determine AM1-2, which is their model of plate velocities relative to the hotspots. AM1-2 is consistent with Minster and Jordan's relative plate velocity model RM2. Here the authors compare HS2-NUVEL1 with AM1-2 and examine how their differences relate to differences between NUVEL-1 and RM2. HS2-NUVEL1 plate velocities relative to the hotspots are mainly similar to those of AM1-2. Minor differences between the two models include the following: (1) in HS2-NUVEL1 the speed of the partly continental, apparently non-subducting Indian plate is greater than that of the purely oceanic, subducting Nazca plate; (2) in places the direction of motion of the African, Antarctic, Arabian, Australian, Caribbean, Cocos, Eurasian, North American, and South American plates differs between models by more than 10{degree}; (3) in places the speed of the Australian, Caribbean, Cocos, Indian, and Nazca plates differs between models by more than 8 mm/yr. Although 27 of the 30 RM2 Euler vectors differ with 95% confidence from those of NUVEL-1, only the AM1-2 Arabia-hotspot and India-hotspot Euler vectors differ with 95% confidence from those of HS2-NUVEL1. Thus, substituting NUVEL-1 for RM2 in the inversion for plate velocities relative to the hotspots changes few Euler vectors significantly, presumably because the uncertainty in the velocity of a plate relative to the hotspots is much greater than the uncertainty in its velocity relative to other plates.

  4. Cretaceous to present kinematics of the Indian, African and Seychelles plates

    NASA Astrophysics Data System (ADS)

    Eagles, Graeme; Hoang, Ha H.

    2014-01-01

    An iterative inverse model of seafloor spreading data from the Mascarene and Madagascar basins and the flanks of the Carlsberg Ridge describes a continuous history of Indian-African Plate divergence since 84 Ma. Visual-fit modelling of conjugate magnetic anomaly data from near the Seychelles platform and Laxmi Ridge documents rapid rotation of a Seychelles Plate about a nearby Euler pole in Palaeocene times. As the Euler pole migrated during this rotation, the Amirante Trench on the western side of the plate accommodated first convergence and later divergence with the African Plate. The unusual present-day morphology of the Amirante Trench and neighbouring Amirante Banks can be related to crustal thickening by thrusting and folding during the convergent phase and the subsequent development of a spreading centre with a median valley during the divergent phase. The model fits FZ trends in the north Arabian and east Somali basins, suggesting that they formed in India-Africa Plate divergence. Seafloor fabric in and between the basins shows that they initially hosted a segmented spreading ridge that accommodated slow plate divergence until 71-69 Ma, and that upon arrival of the Deccan-Réunion plume and an increase to faster plate divergence rates in the period 69-65 Ma, segments of the ridge lengthened and propagated. Ridge propagation into the Indian continental margin led first to the formation of the Laxmi Basin, which accompanied extensive volcanism onshore at the Deccan Traps and offshore at the Saurashtra High and Somnath Ridge. A second propagation episode initiated the ancestral Carlsberg Ridge at which Seychelles-India and India-Africa Plate motions were accommodated. With the completion of this propagation, the plate boundaries in the Mascarene Basin were abandoned. Seafloor spreading between this time and the present has been accommodated solely at the Carlsberg Ridge.

  5. The African Plate: A history of oceanic crust accretion and subduction since the Jurassic

    NASA Astrophysics Data System (ADS)

    Gaina, C.; Torsvik, T. H.; Labails, C.; van Hinsbergen, D.; Werner, S.; Medvedev, S.

    2012-04-01

    Initially part of Gondwana and Pangea, and now surrounded almost entirely by spreading centres, the African plate moved relatively slowly for the last 200 million years. Yet both Africa's cratons and passive margins were affected by tectonic stresses developed at distant plate boundaries. Moreover, the African plate was partly underlain by hot mantle (at least for the last 300 Ma) - either a series of hotspots or a superswell, or both - that contributed to episodic volcanism, basin-swell topography, and consequent sediment deposition, erosion, and structural deformation. A systematic study of the African plate boundaries since the opening of surrounding oceanic basins is presently lacking. This is mainly because geophysical data are sparse and there are still controversies regarding the ages of oceanic crust. The publication of individual geophysical datasets and more recently, global Digital Map of Magnetic Anomalies (WDMAM, EMAG2) prompted us to systematically reconstruct the ages and extent of oceanic crust around Africa for the last 200 Ma. Location of Continent Ocean Boundary/Continent Ocean Transition and older oceanic crust (Jurassic and Cretaceous) are updates in the light of gravity, magnetic and seismic data and models of passive margin formation. Reconstructed NeoTethys oceanic crust is based on a new model of microcontinent and intr-oceanic subduction zone evolution in this area.The new set of oceanic palaeo-age grid models constitutes the basis for estimating the dynamics of oceanic crust through time and will be used as input for quantifying the paleo-ridge push and slab pull that contributed to the African plate palaeo-stresses and had the potential to influence the formation of sedimentary basins.

  6. Convection pattern and stress system under the African plate

    NASA Technical Reports Server (NTRS)

    Liu, H.-S.

    1977-01-01

    Studies on tectonic forces from satellite-derived gravity data have revealed a subcrustal stress system which provides a unifying mechanism for uplift, depression, rifting, plate motion and ore formation in Africa. The subcrustal stresses are due to mantle convection. Seismicity, volcanicity and kimberlite magmatism in Africa and the development of the African tectonic and magnetic features are explained in terms of this single stress system. The tensional stress fields in the crust exerted by the upwelling mantle flows are shown to be regions of structural kinship characterized by major concentration of mineral deposits. It is probable that the space techniques are capable of detecting and determining the tectonic forces in the crust of Africa.

  7. Cycloid kinematics of relative plate motion

    SciTech Connect

    Cronin, V.S.

    1987-11-01

    The trajectory of a point on one plate as observed from another plate is generally a complex curve and not a small circle around a single axis of relative motion, as is commonly assumed. The shape of the relative-motion path is given the general name spherical cycloid because of its morphological similarity to cycloid planetary trajectories described by early astronomers. The cycloid relative-motion model predicts that the following phenomena occur during finite displacements: (1) the relative velocity and the curvature of the trajectory of a point on one plate relative to another plate varies systematically; (2) plates wobble relative to one another; and (3) the angle of convergence and/or divergence varies systematically along the length of any given transform fault. The small-circle relative-motion model, whereby transform faults have been considered lines of pure slip along which crust is conserved, is not generally valid for finite relative displacements.

  8. Computing relative plate velocities: a primer

    SciTech Connect

    Bevis, M.

    1987-08-01

    Standard models of present-day plate motions are framed in terms of rates and poles of rotation, in accordance with the well-known theorem due to Euler. This article shows how computation of relative plate velocities from such models can be viewed as a simple problem in spherical trigonometry. A FORTRAN subroutine is provided to perform the necessary computations.

  9. Phanerozoic evolution of plants on the African plate

    NASA Astrophysics Data System (ADS)

    Burgoyne, P. M.; van Wyk, A. E.; Anderson, J. M.; Schrire, B. D.

    2005-10-01

    The Phanerozoic has witnessed major changes, with Africa being an integral part of supercontinental landmass agglomeration forming Gondwana, its amalgamation with smaller landmasses to form Pangaea, and later disintegrating to form the existing continents. At the same time climates, atmosphere, oceanic circulation and tectonic plates shifted. During this upheaval, life was evolving and organisms were adapting and with higher diversity came more ecological interactions, creating more habitats and thus influencing more biological radiation. Plants became more complex, developing from unicellular to multicellular organisms. Moving from water onto land, plants had to cope with desiccation, and features evolved enabling them to do this. Patterns of Phanerozoic plant evolution are strongly driven by major changes in the physical environment, most notably continental drift, climate change and bolide impacts, precipitating massive volcanism and other effects leading to mass global extinctions. The products of this evolution were early land plants during Silurian and Devonian times. Subjected to extinction events and environmental changes, these early plants gave rise to the pteridophytes reaching their diversity peak during the Carboniferous and Permian. After the demise of the pteridophytes, the gymnosperms dominated during the Triassic and Jurassic, followed by the emergence of the angiosperms in the Cretaceous. This melange of factors has produced the present plant diversity on earth, which we will examine in context of the African flora. Plant diversification in Gondwana and Laurasia will be covered focussing on Africa, while factors affecting the vegetation and species composition of the present flora will be discussed.

  10. Geodynamics of the Indian Lithospheric Plate relative to the neighbouring Plates as revealed by Space Geodetic Measurements

    NASA Astrophysics Data System (ADS)

    Krishna, S.; Mathew, J.; Majumdar, R.; Roy, P.; Vinod Kumar, K.

    2014-11-01

    The Indian Plate is highly dynamic in nature which in turn makes the Indo-Eurassian collision zone the foci of most of the historic large magnitude earthquakes. Processing of positional information from continuously observing reference stations is one of the space based geodetic techniques used globally and nationally to understand the crustal dynamics. The present study evaluates the dynamic nature of the Indian plate relative to its adjoining plates using the permanent GPS data (2011 to 2013) of 12 International GNSS Service (IGS), which are spread across the Indian, Eurassian, Australian, Somaliyan and African plates. The data processing was carried out using GAMIT/GLOBK software. The results indicate that the average velocity for the two IGS stations on the Indian Plate (Hyderabad and Bangalore) is 54.25 mm/year towards NE in the ITRF-2008 reference frame. The relative velocity of various stations with respect to the Indian plate has been estimated using the Bangalore station and has been found that the stations in the Eurasian plate (Lhasa, Urumqi, Bishkek and Kitab) are moving with velocity ranging from 25 to 33 mm/year in the SE direction resulting in compressional interaction with the Indian plate. This study reveals and confirms to the previous studies that the Indian- Eurassian-Australian Plates are moving at different relative velocities leading to compressional regimes at their margins leading to seismicity in these zones.

  11. Caribbean tectonics and relative plate motions

    NASA Technical Reports Server (NTRS)

    Burke, K.; Dewey, J. F.; Cooper, C.; Mann, P.; Pindell, J. L.

    1984-01-01

    During the last century, three different ways of interpreting the tectonic evolution of the Gulf of Mexico and the Caribbean have been proposed, taking into account the Bailey Willis School of a permanent pre-Jurassic deep sea basin, the Edward Suess School of a subsided continental terrain, and the Alfred Wegener School of continental separation. The present investigation is concerned with an outline of an interpretation which follows that of Pindell and Dewey (1982). An attempt is made to point out ways in which the advanced hypotheses can be tested. The fit of Africa, North America, and South America is considered along with aspects of relative motion between North and South America since the early Jurasic. Attention is given to a framework for reconstructing Caribbean plate evolution, the evolution of the Caribbean, the plate boundary zones of the northern and southern Caribbean, and the active deformation of the Caribbean plate.

  12. African American Preschoolers' Language, Emergent Literacy Skills, and Use of African American English: A Complex Relation

    ERIC Educational Resources Information Center

    Connor, Carol McDonald; Craig, Holly K.

    2006-01-01

    Purpose: This study examined the relation between African American preschoolers' use of African American English (AAE) and their language and emergent literacy skills in an effort to better understand the perplexing and persistent difficulties many African American children experience learning to read proficiently. Method: African American…

  13. First seamount age evidence for significantly slower African plate motion since 19 to 30 Ma

    NASA Astrophysics Data System (ADS)

    O'Connor, J. M.; Stoffers, P.; van den Bogaard, P.; McWilliams, M.

    1999-09-01

    Resolving the time-space (and compositional) evolution of volcanism along long-lived South Atlantic hotspot trails is important to understanding the connection between hotspot volcanism and mantle plumes. 40Ar/39Ar ages are reported here for rocks dredged from a line of five individual seamounts along an ∼290 km northeast to southwest line extending from the vicinity of Saint Helena Island, and also for Circe Seamount. These seamounts were created in a midplate setting and could have formed rapidly (≤1 Myr). The St. Helena Seamount ages reveal a remarkably linear migration rate of volcanism of 20±1 mm/yr for at least the past 19 Myr, which is interpreted as the absolute motion of the African plate. Because this is much slower than estimated for earlier African plate migration it also represents the first evidence based on seamount ages for a significant deceleration (∼33%) of the African plate since at least 19 Ma. However, this change could have occurred as early as 30 Ma when the limited data for the Tristan/Gough hotspot chain are also considered. This deceleration supports a relationship between African plate speed and the upsurge of hotspot volcanism on the African continent at ∼25 Ma. We suggest that the increased number of oceanic African hotspots between ∼19 and 30 Ma points to a link also between major changes in plate motion and the onset and continuation of oceanic hotspot volcanism. Our study supports the assumption that chains of individual, rapidly (?) formed seamounts have considerably more potential of providing clear insights into how mantle plumes interact with overriding lithosphere than do those consisting of uninterrupted, more massive lines of hotspot volcanism.

  14. The satellite magnetic anomaly of Ahaggar - Evidence for African Plate motion

    NASA Technical Reports Server (NTRS)

    Phillips, R. J.; Brown, C. R.

    1985-01-01

    The Ahaggar volcanic province of North Central Africa is considered a region of excess heat flow (hot spot) and hence elevated Curie isotherm. Using a modified version of the Parker FFT potential field representation, magnetic signals were calculated at Magsat altitudes for models in which the African Plate is both fixed and moving. The moving-plate model extends the Curie isotherm anomaly in the direction of plate motion and provides a satisfactory match to vertical component anomaly data when the magnitude of plate velocity is 0.75 cm/yr. Although the signal levels are marginal for the scalar component anomalies of this region, the same model provides an adequate match to this data set and is clearly preferable to a fixed-plate model.

  15. Phanerozoic within-plate magmatism of North Asia: Absolute paleogeographic reconstructions of the African large low-shear-velocity province

    NASA Astrophysics Data System (ADS)

    Kuz'min, M. I.; Yarmolyuk, V. V.; Kravchinsky, V. A.

    2011-11-01

    The phanerozoic within-plate magmatism of Siberia is reviewed. The large igneous provinces (LIPs) consecutively arising in the Siberian Craton are outlined: the Altai-Sayan LIP, which operated most actively 400-375 Ma ago, the Vilyui LIP, which was formed from the Middle Devonian to the Early Carboniferous, included; the Barguzin-Vitim LIP (305-275 Ma); the Late Paleozoic Rift System of Central Asia (318-250 Ma); the Siberian flood basalt (trap) province and the West Siberian rift system (250-247 Ma); and the East Mongolian-West Transbaikal LIP (230-195 Ma), as well as a number of Late-Mesozoic and Cenozoic rift zones and autonomous volcanic fields formed over the last 160 Ma. The trace-element and isotopic characteristics of the igneous rocks of the above provinces are reviewed; their mantle origin is substantiated and the prevalence of PREMA, EM2, and EM1 mantle magma sources are shown. The paleogeographic reconstructions based on paleomagnetic data assume that the Iceland hot spot was situated beneath the Siberian flood basalts 250 Ma ago and that the mantle plumes retained a relatively stable position irrespective of the movements of the lithospheric plates. At present, the Iceland hot spot occurs near the northern boundary of the African large low shear velocity province (LLSVP). It is suggested that the within-plate Phanerozoic magmatism of Siberia was related to the drift of the continent above the hot spots of the African LLSVP.

  16. Plate Kinematic model of the NW Indian Ocean and derived regional stress history of the East African Margin

    NASA Astrophysics Data System (ADS)

    Tuck-Martin, Amy; Adam, Jürgen; Eagles, Graeme

    2015-04-01

    Starting with the break up of Gondwana, the northwest Indian Ocean and its continental margins in Madagascar, East Africa and western India formed by divergence of the African and Indian plates and were shaped by a complicated sequence of plate boundary relocations, ridge propagation events, and the independent movement of the Seychelles microplate. As a result, attempts to reconcile the different plate-tectonic components and processes into a coherent kinematic model have so far been unsatisfactory. A new high-resolution plate kinematic model has been produced in an attempt to solve these problems, using seafloor spreading data and rotation parameters generated by a mixture of visual fitting of magnetic isochron data and iterative joint inversion of magnetic isochron and fracture zone data. Using plate motion vectors and plate boundary geometries derived from this model, the first-order regional stress pattern was modelled for distinct phases of margin formation. The stress pattern is correlated with the tectono-stratigraphic history of related sedimentary basins. The plate kinematic model identifies three phases of spreading, from the Jurassic to the Paleogene, which resulted in the formation of three main oceanic basins. Prior to these phases, intracontinental 'Karoo' rifting episodes in the late Carboniferous to late Triassic had failed to break up Gondwana, but initiated the formation of sedimentary basins along the East African and West Madagascan margins. At the start of the first phase of spreading (183 to 133 Ma) predominantly NW - SE extension caused continental rifting that separated Madagascar/India/Antarctica from Africa. Maximum horizontal stresses trended perpendicular to the local plate-kinematic vector, and parallel to the rift axes. During and after continental break-up and subsequent spreading, the regional stress regime changed drastically. The extensional stress regime became restricted to the active spreading ridges that in turn adopted trends

  17. Interactions between Eurasian/African and Arabian plates: Eskişehir Fault, NW Turkey

    NASA Astrophysics Data System (ADS)

    Özden, Süha; Gündoğdu, Erdem; Bekler, Tolga

    2015-11-01

    The Eskişehir Fault is an active right-lateral widespread intra-continental deformation zone which separates central western Anatolia from the Aegean domain. The inversion of fault slip vectors along the Eskişehir Fault yields a strike-slip stress state with NW-trending σHmax (σ1) and NE-trending σHmin (σ3) axes since the Early Pliocene. A change in strike-slip faulting under a compressional stress regime: from old transpression to young transtension, probably occurred in the Quaternary. The inversion of the earthquake source mechanism indicates that the transtensional stress regime continues up to the present. The İnönü and Eskişehir Basins developed under the transtensional stress regime producing consistent and local normal faulting with a continuing NE-trending σHmin (σ3). The stress regime change resulted in a decrease in σHmax (σ1) and/or an increase in σHmin (σ3) stress magnitudes due to coeval influence of the superimposed plate forces and the interaction of three plates (Eurasian/African/Arabian): (1) continental collision of Eurasian/Arabian plates with Anatolian block in the east, (2) westward escape of the Anatolian block by anticlockwise rotation at the west-southwest border of the Eurasian and Arabian/African plates and (3) a complex subduction process between African and Eurasian plates along the Aegean (Hellenic) and the Cyprus arcs which favors western extrusion of the Anatolian block in the eastern Mediterranean region.

  18. African plate motions constraining and Euler pole determination using permanent GPS data

    NASA Astrophysics Data System (ADS)

    Deprez, A.; Masson, F.; Doubre, C.; Ulrich, P.

    2012-04-01

    IPGS-EOST, CNRS-Université de Strasbourg, 5 rue Descartes, 67084 Strasbourg Cedex France. GPS data of permanent stations in Africa allowed us to calculate the position time series and the absolute velocity of many points on this continent during a twelve-year period (1999-2011). The data processing was made thanks to the GAMIT/GLOBK software. The results lead us to select reliable sites presenting a quantity of data large enough to limit the uncertainty. We took care too that this sites did not undergo local deformation and, in particular, that they were far from the plate boundaries. Then we adopted a technique based on William's method to remove the data jumps and the seasonal variations from the position time series. Station sets was brought together function of their position and of plate and micro-plate boundaries from precedents studies. The main conclusions of this velocity field study were as follows: (1) We achieve, with coherent data samples, to find pole coordinates for plates and micro-plates defined by Stamps et al. (2007). These coordinates differ slightly from values found in precedent studies (Altamimi et al., 2012 (in review); Stamps et al., 2007), which were taken as a priori values. (2) Many African stations were too recent to give reliable velocity and the pole coordinate accuracy could be improved in the next few years. (3) The presence of large zones of local deformation particularly on both sides of the East African Rift prevents from the use of many data for the pole determination.

  19. Seismotectonic features of the African plate: the possible dislocation of a continent

    NASA Astrophysics Data System (ADS)

    Meghraoui, Mustapha

    2014-05-01

    , the Libyan rifting and Maghreb thrusting. Although bearing a relatively slow deformation with regards to the East Africa Rift System, the Nubia plate previously considered as a homogeneous tectonic block appears to be dislocating progressively also forming a system of microplates. A synthesis of earthquake studies and regional deformation exposed in a seismotectonic map hitherto serves as a basis for the seismic hazard evaluations and the reduction of seismic risks. * IGCP/SIDA: International Geoscience Program/Swedish International Cooperation Authority http://www.unesco.org/science/IGCP IGCP-601 Working Group: Paulina Amponsah (Ghana Atomic Energy Commission), Atalay Ayele (Addis Ababa University, Ethiopia), Bekoa Ateba (Inst. of Geol. and Min. Res., Buea, Cameroon), Abdelhakim Ayadi (CRAAG, Algeria), Abdunnur Bensuleman (University of Tripoli, Libya), Damien Delvaux (Royal Museum for Central Africa, Tervuren, Belgium), Mohamed El Gabry (National Research Institute of Geophysics, Cairo, Egypt), Rui-Manuel Fernandes (Universidade da Beira Interior, Portugal), Mustapha Meghraoui (IPG Strasbourg, France), Vunganai Midzi & Magda Roos (Council for Geoscience, Pretoria, South Africa), and Youssef Timoulali (CNRST, Rabat, Morocco).

  20. Southern Ocean hotspot tracks and the Cenozoic absolute motion of the African, Antarctic, and South American plates

    NASA Astrophysics Data System (ADS)

    Hartnady, C. J. H.; le Roex, A. P.

    1985-10-01

    A detailed analysis, based on an Antarctica-Africa finite reconstruction at chron C29 (64 Ma), an assumption of no relative wander between the Marion/Prince Edward and Tristan hotspots, and on recently revised bathymetric maps of the Southern Ocean region, shows that the fixed hotspot reference frame is tenable for "absolute" plate motions. Bouvet hotspot, and probably Trinidade as well, also shows little or no Cenozoic relative motion. Contrary to previous models. Bouvet hotspot is unrelated to the Meteor Rise-Cape Rise seamount chain. Instead, the bathymetric data, when compared with the predicted hotspot tracks, indicate another hotspot exists near the southernmost South Atlantic spreading ridge segment. New geochemical evidence from the latter region supports this hypothesis in showing the effects of "plume enrichment" from a source that is compositionally distinct from Bouvet. The peculiar zig-zag shape of the Cape Rise-Meteor Rise lineament is the result of this hotspot crossing the active transform segment of the Falkland-Agulhas Fracture Zone in Late Mesozoic times, followed by an early Cenozoic ridge-jump to the pre-weakened trace on the then South American plate. From the averaged Cenozoic absolute motions of the African, Antarctic, and South American plates, it is evident that Antarctica has been most nearly stationary in an absolute motion sense.

  1. Inherited segmentation of the Iberian-African margins and tectonic reconstruction of a diffuse plate boundary.

    NASA Astrophysics Data System (ADS)

    Fernàndez, Manel; Torne, Montserrat; Vergés, Jaume; Casciello, Emilio

    2016-04-01

    Diffuse plate-boundary regions are characterized by non-well defined contacts between tectonic plates thus making difficult their reconstruction through time. The Western Mediterranean is one of these regions, where the convergence between the African and Iberian plates since Late Cretaceous resulted in the Betic-Rif arcuate orogen, the Gulf of Cadiz imbricate wedge, and the Alboran back-arc basin. Whereas the Iberia-Africa plate boundary is well defined west to the Gorringe Bank and along the Gloria Fault, it becomes much more diffuse eastwards with seismicity spreading over both the south-Iberian and north-African margins. Gravity data, when filtered for short wavelengths, show conspicuous positive Bouguer anomalies associated with the Gorringe Bank, the Gulf of Cadiz High and the Ronda/Beni-Bousera peridotitic massifs reflecting an inherited Jurassic margin segmentation. The subsequent Alpine convergence between Africa and Iberia reactivated these domains, producing crustal-scale thrusting in the Atlantic segments and eventually subduction in the proto-Mediterranean segments. The Jurassic segmentation of the Iberia-Africa margins substantiates the double-polarity subduction model proposed for the region characterized by a change from SE-dipping polarity in the Gorringe, Gulf of Cadiz and Betic-Rif domains, to NW-dipping polarity in the proto-Algerian domain. Therefore, the Algerian and Tyrrhenian basins in the east and the Alboran basin in the west are the result of SSE-E and NW-W retreating slabs of oceanic and/or hyper-extended Tethyan domains, respectively.

  2. Indian and African plate motions driven by the push force of the Réunion plume head.

    PubMed

    Cande, Steven C; Stegman, Dave R

    2011-07-01

    Mantle plumes are thought to play an important part in the Earth's tectonics, yet it has been difficult to isolate the effect that plumes have on plate motions. Here we analyse the plate motions involved in two apparently disparate events--the unusually rapid motion of India between 67 and 52 million years ago and a contemporaneous, transitory slowing of Africa's motion--and show that the events are coupled, with the common element being the position of the Indian and African plates relative to the location of the Réunion plume head. The synchroneity of these events suggests that they were both driven by the force of the Réunion plume head. The recognition of this plume force has substantial tectonic implications: the speed-up and slowdown of India, the possible cessation of convergence between Africa and Eurasia in the Palaeocene epoch and the enigmatic bends of the fracture zones on the Southwest Indian Ridge can all be attributed to the Réunion plume. PMID:21734702

  3. Indian and African plate motions driven by the push force of the Réunion plume head.

    PubMed

    Cande, Steven C; Stegman, Dave R

    2011-07-06

    Mantle plumes are thought to play an important part in the Earth's tectonics, yet it has been difficult to isolate the effect that plumes have on plate motions. Here we analyse the plate motions involved in two apparently disparate events--the unusually rapid motion of India between 67 and 52 million years ago and a contemporaneous, transitory slowing of Africa's motion--and show that the events are coupled, with the common element being the position of the Indian and African plates relative to the location of the Réunion plume head. The synchroneity of these events suggests that they were both driven by the force of the Réunion plume head. The recognition of this plume force has substantial tectonic implications: the speed-up and slowdown of India, the possible cessation of convergence between Africa and Eurasia in the Palaeocene epoch and the enigmatic bends of the fracture zones on the Southwest Indian Ridge can all be attributed to the Réunion plume.

  4. The Syntax of Zero in African American Relative Clauses

    ERIC Educational Resources Information Center

    Sistrunk, Walter

    2012-01-01

    African American relative clauses are distinct from Standard English relative clauses in allowing zero subject relatives and zero appositive relatives. Pesetsky and Torrego's (2003) (P&T) analysis of the subject-nonsubject asymmetry in relative clauses accounts for zero object relatives while restricting zero subject relatives. P&T…

  5. Hypertension in African Americans and its related chronic diseases.

    PubMed

    Moulton, Sandra A

    2009-01-01

    Hypertension is prevalent in African Americans and it is associated with three chronic diseases namely; stroke, kidney disease, and heart disease. The literature examines the prevalence of hypertension in African Americans in relation to other groups. Not only do African Americans have higher rates of organ damage, but also stroke and heart disease mortality caused, at least in part, by hypertension. Health professionals, especially nurses, should be proactive in detecting hypertension in African Americans and be more aggressive in controlling and treating this high-risk group. Health education regarding the dangers of hypertension should be the primary focus of healthcare professionals to decrease and prevent mortality and morbidity in the African Americans with hypertension.

  6. Relative motions between oceanic plates of the Pacific Basin

    NASA Astrophysics Data System (ADS)

    Engebretson, David C.; Cox, Allan; Gordon, Richard G.

    1984-11-01

    Appendix tables are available with entire article on microfiche. Order from American Geophysical Union, 2000 Florida Avenue, N.W., Washington, D.C., 20009. Document B84-012; $2.50. Payment must accompany order. Relative motion poles describing the displacement histories between the Pacific plate and once adjacent oceanic plates (Farallon, Kula, Izanagi I, Izanagi II, and Phoenix) were derived for the late Mesozoic and Cenozoic eras. Because fracture zone and magnetic anomaly data are generally available from the Pacific plate but not from adjacent plates, a new method of analysis for onesided data was required. This analysis produced stage poles and rates of relative plate motion and estimates of their confidence regions. The following are the main conclusions drawn from our analysis: (1) For time intervals of the order of 107 years, termed stages, relative motion poles for plate pairs remained nearly fixed. Between stages, shifts in poles were commonly both large and abrupt. Within stages, rates of plate motion were commonly observed to change markedly, indicating that plates changed speed more frequently than they changed direction. (2) The relative motions of all of the plates analyzed changed at about chron M11 (135 Ma), chron 34 (85 Ma), and chron 25 (56 Ma). (3) During the Early Cretaceous there were five oceanic plates in the Pacific basin rather than the four recognized by previous workers. (4) To determine the number of Farallon plates that existed to the east of the Pacific plate during the time interval from chron 34 (85 Ma) to chron 25 (56 Ma), fracture zones and magnetic anomalies that record Pacific-Farallon spreading from the northern, central, and southern Pacific plate were analyzed separately and collectively. The analysis shows that a single Pacific-Farallon relative motion pole and a single rate are consistent with all of the data. (5) Spreading rates along the Pacific-Kula ridge decreased markedly between chrons 32b and 25 (72-56 Ma), probably

  7. A possible relation between pulses of platform activation and plate kinematics

    NASA Astrophysics Data System (ADS)

    Sadowski, Georg Robert

    1987-11-01

    The idea of the cyclic evolution of platforms may have an explanation related to plate kinematics as a function of two main parameters: the spreading rate and rotation pole switches. These kinematic parameters as defined by other authors studying the South Atlantic appear to bear a coherent relationship with pulses of platform activation in South America and Africa. In Gondwana's history, after its break-up at least four major peaks of volcano-tectonic activity on the continents seem to be related to important changes in position of the rotation poles and the spreading rates of the South American and African plates. Mantle convection patterns such as those suggested by McKenzie on the Pacific floor can be seen as feasible mechanisms for explaining the origin and shape of large syneclises and archings.

  8. A wide-angle seismic survey of the Hecataeus Ridge, south of Cyprus: a microcontinental block from the African plate docked in a subduction zone?

    NASA Astrophysics Data System (ADS)

    Rahimi, Ayda; Welford, Kim; Hall, Jeremy; Hübscher, Christian; Louden, Keith; Ehrhardt, Axel

    2013-04-01

    Cyprus lies at the southern edge of the Aegean-Anatolian microplate, caught in the convergence of Africa and Eurasia. Subduction of the African plate below Cyprus has probably ceased and this has been attributed to the docking in the subduction zone of the Eratosthenes Seamount microcontinental fragment on the northern edge of the African plate. In early 2010, on R.V. Maria S. Merian, we conducted a wide-angle seismic survey to test the hypothesis that the Hecataeus Ridge, another possible microcontinental block lying immediately offshore SE Cyprus, might be related to an earlier docking event. The upper crust of southern Cyprus is dominated by ophiolites, with seismic velocities of up to 7 km s-1. A wide angle seismic profile along Hecataeus Ridge was populated with 15 Canadian and German ocean-bottom seismographs at 5 km intervals and these recorded shots from a 6000 cu. in. air gun array, fired approximately every 100 m. Rough topography of the seabed has made picking of phases and their modelling a demanding task. Bandpass and coherency filtering have enabled us to pick phases out to around 80 km. Tomographic inversion of short-range first arrivals provided an initial model of the shallow sub-seabed structure. Forward modelling by ray-tracing, using the code of Zelt and Smith, was then used to model crustal structure down to depths of around 20 km, with occasional evidence of reflections from deeper boundaries (Moho?). Modelling results provide good control on P-wave velocities in the top 20 km and some indications of deeper events. There is no evidence of true velocities approaching 7 km/s in the top 20 km below the Ridge that might indicate the presence of ophiolitic rocks. Regional gravity and magnetic field data tend to support this proposition. We thus conclude that Hecataeus Ridge is not composed of characteristically ophiolitic, Cyprus (upper plate) crust, and it might well be derived from the African (lower) plate.

  9. Development of transtensional and transpressive plate boundaries due to noncircular (cycloid) relative plate motion

    SciTech Connect

    Cronin, V.S. )

    1990-05-01

    The trace of a transform fault commonly is assumed to be circular and concentric with the finite relative motion of the plates adjacent to the fault. These assumptions have led to controversy as the transform fault label has been applied to the San Andreas fault in California because the San Andreas fault is neither circular nor concentric with the motion of the Pacific plate relative to the North American plate. The assumption of circular relative plate motion over a finite time interval is not generally valid. When finite relative plate motion is not circular, the length and orientation of a transform fault must change through time. The length and orientation of ridge-ridge transform faults in oceanic crust evolve through the migration, propagation, and abandonment of ridge segments. Transform faults that bound continental crust evolve differently than do transform faults along mid-ocean ridges because continental transform faults typically do not have ridges at both ends and because of the rheological differences between oceanic and continental crust. Along continent-continent transform faults in which the initial displacement is entirely strike slip, later displacements will be progressively more divergent or convergent (i.e., transtensive or transpressive). Transtension can result in the development of deep basins with high heat flow. Transpression can result in folding, reverse faulting, and decoupling of the crust from its lower crustal or mantle lithosphere in the region adjacent to the transform fault. Regardless of whether the transform boundary becomes transtensional or transpressional, the boundary evolves from a discrete transform fault to a broader, structurally complex accommodation zone (sensu lato).

  10. The San Andreas fault experiment. [gross tectonic plates relative velocity

    NASA Technical Reports Server (NTRS)

    Smith, D. E.; Vonbun, F. O.

    1973-01-01

    A plan was developed during 1971 to determine gross tectonic plate motions along the San Andreas Fault System in California. Knowledge of the gross motion along the total fault system is an essential component in the construction of realistic deformation models of fault regions. Such mathematical models will be used in the future for studies which will eventually lead to prediction of major earthquakes. The main purpose of the experiment described is the determination of the relative velocity of the North American and the Pacific Plates. This motion being so extremely small, cannot be measured directly but can be deduced from distance measurements between points on opposite sites of the plate boundary taken over a number of years.

  11. Is Nubia plate rigid? A geodetic study of the relative motion of different cratonic areas within Africa.

    NASA Astrophysics Data System (ADS)

    Njoroge, M. W.; Malservisi, R.; Hugentobler, U.; Mokhtari, M.; Voytenko, D.

    2014-12-01

    Plate rigidity is one of the main paradigms of plate tectonics and a fundamental assumption in the definition of a global reference frame as ITRF. Although still far for optimal, the increased GPS instrumentation of the African region can allow us to understand how rigid one of the major plate can be. The presence of diffused band of seismicity, the Cameroon volcanic line, Pan African Kalahari orogenic belt and East Africa Rift suggest the possibility of relative motion among the different regions within the Nubia. The study focuses on the rigidity of Nubia plate. We divide the plate into three regions: Western (West Africa craton plus Nigeria), Central (approximately the region of the Congo craton) and Southern (Kalahari craton plus South Africa) and we utilize Euler Vector formulation to study internal rigidity and eventual relative motion. Developing five different reference frames with different combinations of the 3 regions, we try to understand the presence of the relative motion between the 3 cratons thus the stability of the Nubia plate as a whole. All available GPS stations from the regions are used separately or combined in creation of the reference frames. We utilize continuous stations with at least 2.5 years of data between 1994 and 2014. Given the small relative velocity, it is important to eliminate eventual biases in the analysis and to have a good estimation in the uncertainties of the observed velocities. For this reason we perform our analysis using both Bernese and Gipsy-oasis codes to generate time series for each station. Velocities and relative uncertainties are analyzed using the Allan variance of rate technique, taking in account for colored noise. An analysis of the color of the noise as function of latitude and climatic region is also performed to each time series. Preliminary results indicate a slight counter clockwise motion of West Africa craton with respect to South Africa Kalahari, and South Africa Kalahari-Congo Cratons. In addition

  12. Understanding lithospheric stresses: systematic analysis of controlling mechanisms with applications to the African Plate

    NASA Astrophysics Data System (ADS)

    Medvedev, Sergei

    2016-06-01

    Many mechanisms control the state of stress within Earth plates. First-order well-known mechanisms include stresses induced by lateral variations of lithospheric density structure, sublithospheric tractions, ridge push, and subduction pull. In this study, we attempt to quantify the influence of these mechanisms to understand the origin of stresses in the lithosphere, choosing the African plate (TAP) as an example. A finite-element based suite, Proshell, was developed to combine several data sets, to estimate the gravitational potential energy (GPE) of the lithosphere, and to calculate stresses acting on the real (non-planar) geometry of TAP. We introduce several quantitative parameters to measure the degree of fit between the model and observations. Our modelling strategy involves nine series of numerical experiments. We start with the simplest possible model and then, step by step, build it up to be a more physically realistic model, all the while discussing the influence of each additional component. The starting (oversimplified) model series (1) is based on the CRUST2 data set for the crust, and a half-space-cooling approximation of the lithospheric mantle. We then describe models (series 2-5) that account for lithospheric mantle density heterogeneities to build a more reliable GPE model. The consecutive series involve basal traction from the convective mantle (series A, C), and the rheological heterogeneity of the TAP via variations in its effective elastic thickness (series B, C). The model quality reflects the increase in complexity between series with an improving match toobserved stress regimes and directions. The most complex model (series D) also accounts for the bending stresses in the elastic lithosphere and achieves a remarkably good fit to observations. All of our experiments were based on the iteration of controlling parameters in order to achieve the best fit between modelled and observed stresses, always considering physically feasible values. This

  13. Understanding lithospheric stresses: systematic analysis of controlling mechanisms with applications to the African Plate

    NASA Astrophysics Data System (ADS)

    Medvedev, Sergei

    2016-10-01

    Many mechanisms control the state of stress within Earth plates. First-order well-known mechanisms include stresses induced by lateral variations of lithospheric density structure, sublithospheric tractions, ridge push and subduction pull. In this study, we attempt to quantify the influence of these mechanisms to understand the origin of stresses in the lithosphere, choosing the African plate (TAP) as an example. A finite-element based suite, Proshell, was developed to combine several data sets, to estimate the gravitational potential energy (GPE) of the lithosphere and to calculate stresses acting on the real (non-planar) geometry of TAP. We introduce several quantitative parameters to measure the degree of fit between the model and observations. Our modelling strategy involves nine series of numerical experiments. We start with the simplest possible model and then, step by step, build it up to be a more physically realistic model, all the while discussing the influence of each additional component. The starting (oversimplified) model series (1) is based on the CRUST2 data set for the crust and a half-space-cooling approximation of the lithospheric mantle. We then describe models (series 2-5) that account for lithospheric mantle density heterogeneities to build a more reliable GPE model. The consecutive series involve basal traction from the convective mantle (series A, C) and the rheological heterogeneity of the TAP via variations in its effective elastic thickness (series B, C). The model quality reflects the increase in complexity between series with an improving match to observed stress regimes and directions. The most complex model (series D) also accounts for the bending stresses in the elastic lithosphere and achieves a remarkably good fit to observations. All of our experiments were based on the iteration of controlling parameters in order to achieve the best fit between modelled and observed stresses, always considering physically feasible values. This

  14. Gender as a Moderator of the Relation between Race-Related Stress and Mental Health Symptoms for African Americans

    ERIC Educational Resources Information Center

    Greer, Tawanda M.; Laseter, Adrian; Asiamah, David

    2009-01-01

    The present study tested gender as a moderator of the relationship between race-related stress and mental health symptoms among African American adults. Because African American women are exposed to stressors associated with race and gender, we hypothesized that African American women would have higher levels of race-related stress and more severe…

  15. Evidence for relative motions between the Indian and Australian Plates during the last 20 m.y. from plate tectonic reconstructions: Implications for the deformation of the Indo-Australian Plate

    NASA Astrophysics Data System (ADS)

    Royer, Jean-Yves; Chang, Ted

    1991-07-01

    We use plate tectonic reconstructions to establish whether motions between India and Australia occurred since chron 18 (43 Ma). We test the Africa/Antarctica/Australia/India plate circuit closure at chrons 5 (10 Ma), 6 (21 Ma) and 13 (36 Ma) using a compilation of magnetic anomalies and fracture zone traces from the Southeast, Southwest, Central Indian and the Carlsberg ridges. Additional reconstructions at chrons 23 (55 Ma) and 26 (61 Ma) are used to estimate the overall motion between India and Australia. Relative motions between the Indian and Australian plates are estimated using the plate circuit India → Africa → Australia. A new statistical approach, based on spherical regression analyses, is used to assess the uncertainty of the "best-fitting" finite rotations from the uncertainties in the data. The uncertainty in a rotation is described by a covariance matrix directly related to the geometry of the reconstructed plate boundary, to the distribution and estimated errors of the data points along it. Our parameterization of the rotations allows for simple combination of the rotation uncertainties along a plate circuit path. Results for chron 5 are remarkably consistent with present-day kinematics in the Indian Ocean, except that the Arabian and Indian plates are found to be separate plates. Comparisons of the motions between the Indian and African plates across the Carlsberg Ridge with that between the Australian and African plates across the Central Indian Ridge evidence a significant counterclockwise rotation of the Australian plate relative to the Indian plate about a pole located in the Central Indian Basin. The determinations are consistent for chrons 26, 13, 6 and 5. Determination at chron 23 is different but questionable due to the small number of available data. We propose two alternative solutions that both predict convergence within the Wharton and Central Indian basins and extension in the vicinity of the Chagos-Laccadive Ridge. The first

  16. Recent faulting and active shortening of the Middle Atlas Mountains, Morocco, within the diffuse African-Eurasian plate boundary

    NASA Astrophysics Data System (ADS)

    Rigby, M.; Gomez, F.; Zakir, A.; Hahou, Y.; Jabour, N.

    2007-12-01

    The NE-SW trending Middle Atlas Mountains are an active intracontinental mountain belt within the diffuse African - Eurasian plate boundary. The mountain belt is obliquely oriented to the NNW-SSE direction of Late Cenozoic plate convergence. Both shear and compressional features are exhibited with apparent slip partitioning: Folding and thrusting is concentrated in the Folded Middle Atlas, whereas strike-slip dominates in the Tabular Middle Atlas. In the central part of the Folded Middle Atlas, fault scarps of Quaternary alluvium, including a 4.5 meter (probably composite) scarp and a 1 meter (possibly single event) scarp, attest to recent faulting along the mountain front. Detailed topographic mapping of the scarps provides a basis for geomorphic analysis and degradation modeling. Furthermore, the reconstruction of longitudinal stream terrace profiles helps constrain a long term deformation history. Radiocarbon and pending cosmogenic dates provide age constraints on the faulted surfaces and the multiple stream terraces in the area. To place these active tectonic observations in a larger context, the fault and fold geometry has been assessed by completing a 10 km structural transect across the frontal thrust, providing basis for the construction of a balanced cross-section. By combining the structural geometry with the uplift rate, a minimum estimate of the rate of horizontal shortening in the Middle Atlas can be evaluated. Preliminary results suggest the Middle Atlas may accommodate 5 - 10 percent of the total 4.5 mm/yr convergence between the African and Eurasian plates. These results demonstrate that the Middle Atlas Mountains are a integral part of the diffuse plate boundary, as well as suggesting a modest level of earthquake hazard in the region.

  17. 77 FR 20846 - Certain Food Containers, Cups, Plates, Cutlery, and Related Items and Packaging Thereof...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-06

    ... COMMISSION Certain Food Containers, Cups, Plates, Cutlery, and Related Items and Packaging Thereof... importation of certain food containers, cups, plates, cutlery, and related items and packaging thereof by... importation of certain food containers, cups, plates, cutlery, and related items and packaging thereof...

  18. 77 FR 14423 - Certain Food Containers, Cups, Plates, Cutlery, and Related Items, and Packaging Thereof; Notice...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-09

    ... COMMISSION Certain Food Containers, Cups, Plates, Cutlery, and Related Items, and Packaging Thereof; Notice... Trade Commission has received a complaint entitled Certain Food Containers, Cups, Plates, Cutlery, and... containers, cups, plates, cutlery, and related items, and packaging thereof. The complaint names...

  19. The Rift Valley of African Plate in Elasto-Plastic Creeping over Magma Motion

    NASA Astrophysics Data System (ADS)

    Nakamura, Shigehisa

    2016-04-01

    This is a brief note to a problem on the Rift Valley in the eastern Africa. It is said that this valley was formed in an age 20,000,000 years before present though the valley is yet continuing to move eastward at an annual rate of about 5 cm/year in a geographical trend. Adding to some of the scientists tell that the separation threat of the easternAfrica from the mother land of the Africa under the effect of African crust motion over the magma. However, it is now geological understanding that the land of the Africa has been kept its basic coastal configulation in geographic pattern since the time more than 20,000,000 years before present. Sothat, it is hard to consider the above noted African land separation by part could be in the next age in a time scale of 20,000,000 years. As far as, we concern the geographic data obtaoned by the ground based survey of the African typical mountain peaks, the highest mountain peak 5885m (in 1980) is for Kilimanjaro, Kibo Peak though one of the scientific almanacs tells us its peak height as 5890m (in 2009). As for the Mount Kenia, the peak height is as 5199m (in 1980) and 5200m(in 2009). At a glance, it looks to be a trend in altimetry of the African typical mountain. Now, what trends are noted for the peak heights could be taken to suggesting the geological activity on the earth surface to maintain in a spherical shape approximately on the orbit around the Sun. In these several ten years, the digitizing of the data has been promoted even for the topographic patterns on the earth though its time scaling is extremely short comparing to the geological time scaling. Now, it should be found what is effective to monitor any trends of the African crust in motion as well as variations of the mountain peaks.

  20. Race-related stress, quality of life indicators, and life satisfaction among elderly African Americans.

    PubMed

    Utsey, Shawn O; Payne, Yasser A; Jackson, Ebonique S; Jones, Antoine M

    2002-08-01

    This article examined the relationships among race-related stress, quality of life indicators, and life satisfaction among elderly African Americans. A sample of 127 elderly African Americans, consisting of 87 women and 26 men (and 14 missing values), were administered the Index of Race-Related Stress, the Satisfaction With Life Scale, and the 36-item Short-Form Health Survey. Results indicated that elderly African American men and women differed significantly with regard to institutional and collective racism-related stress. In addition, the authors found that institutional racism-related stress was a significant predictor of psychological health in this sample of elderly African Americans.

  1. Work Socialization and Adolescents' Work-Related Values in Single-Mother African American Families

    ERIC Educational Resources Information Center

    Toyokawa, Teru; McLoyd, Vonnie C.

    2013-01-01

    This study examined African American mothers' work socialization messages in relation to adolescents' work-related values. Moderation effects of mother-adolescent relation quality on the linkage between maternal socialization messages and adolescents' outcomes were also examined. Participants were 245 single African American mothers and their…

  2. An Investigation of African American Parents' Perception of School Leaders as It Relates to Parent Engagement and the African American Male Student

    ERIC Educational Resources Information Center

    Currie, Delvon Denise

    2013-01-01

    The purpose of this study was to investigate African American parents' perception of school leaders as it relates to parent engagement and the African American male student. Specifically, this study addressed African American parents' perceptions of the quality of their child's education and the quality of communication they received from their…

  3. Coping with HIV-related stigma in five African countries.

    PubMed

    Makoae, Lucia N; Greeff, Minrie; Phetlhu, René D; Uys, Leana R; Naidoo, Joanne R; Kohi, Thecla W; Dlamini, Priscilla S; Chirwa, Maureen L; Holzemer, William L

    2008-01-01

    People living with HIV (PLWH) and their families are subjected to prejudice, discrimination, and hostility related to the stigmatization of AIDS. This report examines how PLWH cope with HIV-related stigma in the five southern African countries of Lesotho, Malawi, South Africa, Swaziland, and Tanzania. A descriptive qualitative research design was used to explore the experience of HIV-related stigma of PLWH and nurses in 2004. A total of 43 focus groups were conducted with 251 participants (114 nurses, 111 PLWH, and 26 volunteers). In describing incidents of stigma, respondents reported strategies used or observed to cope with those incidents. Nurse reports of coping strategies that they used as well as observed in HIV-infected patients were coded. Coping strategies used by PLWH in dealing with HIV-related stigma were coded. A total of 17 different self-care strategies were identified: restructuring, seeing oneself as OK, letting go, turning to God, hoping, changing behavior, keeping oneself active, using humor, joining a support or social group, disclosing one's HIV status, speaking to others with same problem, getting counseling, helping others to cope with the illness, educating others, learning from others, acquiring knowledge and understanding about the disease, and getting help from others. Coping appears to be self-taught and only modestly helpful in managing perceived stigma.

  4. Stalling Out: The Relative Progress of African Americans.

    ERIC Educational Resources Information Center

    Tidwell, Billy J.

    The socioeconomic progress of African Americans appears to be in a stalled state. This study analyzes the progress of African Americans toward parity with Whites over a 15- to 20-year period in the following areas: (1) employment; (2) economic development; (3) education; (4) health; (5) housing; and (6) political empowerment. For individual…

  5. West African warming: Investigating Temperature Trends and their relation between Precipitation Trends over West African Sahel.

    NASA Astrophysics Data System (ADS)

    LY, M., Jr.

    2014-12-01

    It is now admitted that the West African region faces a lot of constraints due to the comprehensiveness of the high climate variability and potential climate change. This is mainly due to the lack of a large number of datasets and long-term records as summarized in the in the IPCC reports. This paper aims to provide improved knowledge and evidence on current and future climate conditions, for better manage climate variability over seasons and from year to year and strengthen the capacity to adapt to future climate change. In this regards, we analyse the evolution of some extreme temperature and precipitation indices over a large area of West Africa. Prior results show a general warming trend at individual stations throughout the region during the period from 1960 to 2010, namely negative trends in the number of cool nights, and positive trends in the number of warm days and length of warm spells. Trends in rainfall-related indices are not as uniform as the ones in temperatures, rather they display marked multi-decadal variability, as expected. To refine analyses of temperature variations and their relation to precipitation we investigated on cluster analysis aimed at distinguishing different sub-regions, such as continental and coastal, and relevant seasons, such as wet, dry/cold and dry warm. This will contribute to significantly lower uncertainties by developing better and more tailored temperature and precipitation trends to inform the user communities on climate related risks, as well as enhance their resilience to food insecurity and other climate related disasters.

  6. Relative motions of the Australian, Pacific and Antarctic plates estimated by the Global Positioning System

    NASA Technical Reports Server (NTRS)

    Larson, Kristine M.; Freymueller, Jeff

    1995-01-01

    Global Positioning System (GPS) measurements spanning approximately 3 years have been used to determine velocities for 7 sites on the Australian, Pacific and Antarctic plates. The site velocities agree with both plate model predictions and other space geodetic techniques. We find no evidence for internal deformation of the interior of the Australian plate. Wellington, New Zealand, located in the Australian-Pacific plate boundary zone, moves 20 +/- 5 mm/yr west-southwest relative to the Australian plate. Its velocity lies midway between the predicted velocities of the two plates. Relative Euler vectors for the Australia-Antarctica and Pacific-Antarctica plates agree within one standard deviation with the NUVEL-1A predictions.

  7. African ancestry protects against Alzheimer's disease-related neuropathology.

    PubMed

    Schlesinger, D; Grinberg, L T; Alba, J G; Naslavsky, M S; Licinio, L; Farfel, J M; Suemoto, C K; de Lucena Ferretti, R E; Leite, R E P; de Andrade, M P; dos Santos, A C F; Brentani, H; Pasqualucci, C A; Nitrini, R; Jacob-Filho, W; Zatz, M

    2013-01-01

    Previous studies in dementia epidemiology have reported higher Alzheimer's disease rates in African-Americans when compared with White Americans. To determine whether genetically determined African ancestry is associated with neuropathological changes commonly associated with dementia, we analyzed a population-based brain bank in the highly admixed city of São Paulo, Brazil. African ancestry was estimated through the use of previously described ancestry-informative markers. Risk of presence of neuritic plaques, neurofibrillary tangles, small vessel disease, brain infarcts and Lewy bodies in subjects with significant African ancestry versus those without was determined. Results were adjusted for multiple environmental risk factors, demographic variables and apolipoprotein E genotype. African ancestry was inversely correlated with neuritic plaques (P=0.03). Subjects with significant African ancestry (n=112, 55.4%) showed lower prevalence of neuritic plaques in the univariate analysis (odds ratio (OR) 0.72, 95% confidence interval (CI) 0.55-0.95, P=0.01) and when adjusted for age, sex, APOE genotype and environmental risk factors (OR 0.43, 95% CI 0.21-0.89, P=0.02). There were no significant differences for the presence of other neuropathological alterations. We show for the first time, using genetically determined ancestry, that African ancestry may be highly protective of Alzheimer's disease neuropathology, functioning through either genetic variants or unknown environmental factors. Epidemiological studies correlating African-American race/ethnicity with increased Alzheimer's disease rates should not be interpreted as surrogates of genetic ancestry or considered to represent African-derived populations from the developing nations such as Brazil.

  8. Multiple Myeloma Mortality in Relation to Obesity Among African Americans.

    PubMed

    Sonderman, Jennifer S; Bethea, Traci N; Kitahara, Cari M; Patel, Alpa V; Harvey, Chinonye; Knutsen, Synnøve F; Park, Yikyung; Park, Song-Yi; Fraser, Gary E; Teras, Lauren R; Purdue, Mark P; Stolzenberg-Solomon, Rachael Z; Gillanders, Elizabeth M; Palmer, Julie R; Kolonel, Laurence N; Blot, William J

    2016-10-01

    Multiple myeloma (MM) incidence and mortality are higher among African Americans (AAs) than among other population groups. The prevalence of obesity is also elevated among AAs, but few studies have examined risk of this cancer in relation to body size among AAs. We combined data from seven prospective cohorts tracking mortality among 239 597 AA adults and used Cox proportional hazards regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for death because of MM according to body mass index (BMI) at cohort entry, adjusted for age (as time-scale) and sex. Relative to those with normal BMIs (18.5-25 kg/m(2)), mortality increased monotonically as BMI increased, with hazard ratios reaching 1.43 (95% CI = 1.03 to 1.97) for BMIs of 35 kg/m(2) or greater. The findings suggest that obesity is a risk factor for MM and a contributor to the elevated rates and rising incidence trends of MM among AAs in the United States. PMID:27147231

  9. Multiple Myeloma Mortality in Relation to Obesity Among African Americans.

    PubMed

    Sonderman, Jennifer S; Bethea, Traci N; Kitahara, Cari M; Patel, Alpa V; Harvey, Chinonye; Knutsen, Synnøve F; Park, Yikyung; Park, Song-Yi; Fraser, Gary E; Teras, Lauren R; Purdue, Mark P; Stolzenberg-Solomon, Rachael Z; Gillanders, Elizabeth M; Palmer, Julie R; Kolonel, Laurence N; Blot, William J

    2016-10-01

    Multiple myeloma (MM) incidence and mortality are higher among African Americans (AAs) than among other population groups. The prevalence of obesity is also elevated among AAs, but few studies have examined risk of this cancer in relation to body size among AAs. We combined data from seven prospective cohorts tracking mortality among 239 597 AA adults and used Cox proportional hazards regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for death because of MM according to body mass index (BMI) at cohort entry, adjusted for age (as time-scale) and sex. Relative to those with normal BMIs (18.5-25 kg/m(2)), mortality increased monotonically as BMI increased, with hazard ratios reaching 1.43 (95% CI = 1.03 to 1.97) for BMIs of 35 kg/m(2) or greater. The findings suggest that obesity is a risk factor for MM and a contributor to the elevated rates and rising incidence trends of MM among AAs in the United States.

  10. Sisters in the Struggle: African American Female Graduate Students Coping with Racism and Racism-Related

    ERIC Educational Resources Information Center

    Foster, Kelsie

    2013-01-01

    This study examined if coping was predictive of perceived racism and racism related stress of African American female graduate students. Participants were 217 African American female graduate students attending Predominantly White Institutions (PWIs), Hispanic Serving Institutions (HSIs) and Historically Black Colleges and Universities (HBCUs) and…

  11. Research Resources for the Study of African-American and Jewish Relations.

    ERIC Educational Resources Information Center

    Gubert, Betty Kaplan

    1994-01-01

    Discusses New York City library resources for the study of African American and Jewish American relations. Highlights include library collections, access to materials, audio and visual materials, international newspapers, clippings, archives, children's books, and acquisitions. A list of the major libraries for the study of African American and…

  12. Individual and Social Factors Related to Urban African American Adolescents' School Performance

    ERIC Educational Resources Information Center

    Somers, Cheryl L.; Owens, Delila; Piliawsky, Monte

    2008-01-01

    The purpose of this study was to examine factors related to the academic success of urban, African American youth. Participants were 118 African American male and female ninth graders from a large urban high school in the Midwest. A majority of students at the school receive free or reduced lunch. Factors studied were social support from five…

  13. Relations between plate kinematics, slab geometry and overriding plate deformation in subduction zones: insights from statistical observations and laboratory modelling

    NASA Astrophysics Data System (ADS)

    Heuret, A.; Funiciello, F.; Faccenna, C.; Lallemand, S.

    2005-12-01

    3-D laboratory models have been performed in order to investigate the way plates kinematics (subducting and overriding plate absolute motions and the resulting plate convergence rate) influences the geometry of the slab and the overriding plate deformation in subduction zones. In the experiments a viscous plate of silicone (subducting plate) is pushed beneath another plate, which is itself pushed toward or pulled away from the trench (overriding plate), and sinks into a viscous layer of glucose syrup (upper mantle). The subducting and overriding plate velocities explored the variability field of natural subduction plates kinematics. The overriding plate motion exerts a primary role in the control of slab geometries and overriding plate deformation rates. The experiments have revealed two different subduction behaviours: (Style I) the overriding plate moves toward the trench and shortens at high rates, the slab is flat and deflected when reaching the bottom of the box in a forward direction; (Style II) the overriding plates moves away from the trench and shortens at low rates the slab is steep and deflected on the box bottom in a backward direction. To a lesser extent, increasing subducting plate motion is associated to increasing slab dips and overriding plate shortening. Slab geometry and overriding plate deformation are less sensitive to the overall plate convergence rate. These laboratory models behaviours are consistent with statistical analysis performed on natural subduction zones, and enlighten the first order control exerted by the overriding plate absolute motion, on the geometry adopted by the slab and the way the overriding plate deforms.

  14. Determination of Scotia - South America Relative Plate Motion and Crustal Deformation From GPS Geodesy

    NASA Astrophysics Data System (ADS)

    Smalley, R.; Bevis, M.; Kendrick, E.; Dalziel, I.; Taylor, F.; Laurã, E.; Barriga, R.; Casassa, G.; Olivero, E.; Piana, E.

    2001-12-01

    We use Global Positioning System measurements to determine relative plate movements and crustal deformation across the Scotia - South America plate boundary. Our results clearly show active crustal deformation along the South America - Scotia transform boundary in eastern Tierra del Fuego. The 160 km subaerial section of the plate boundary there, to first order, is concentrated on a narrow region best modeled by a simple east-west oriented strike-slip plate boundary. We find no evidence for a significant component of active transpression or transtension between the South America and Scotia plates along this section of the plate boundary. The GPS data also enable us to estimate the first South America -Scotia pole that does not depend on closure for determination of the rotation rate.

  15. Helminth-related Eosinophilia in African Immigrants, Gran Canaria

    PubMed Central

    Pardo, Javier; Carranza, Cristina; Muro, Antonio; Angel-Moreno, Alfonso; Martín, Antonio-Manuel; Martín, Teresa; Hernández-Cabrera, Michele

    2006-01-01

    Of 788 recent African adult immigrants to Las Palmas de Gran Canaria, 213 (27.0%) had eosinophilia. The most frequent causes were filariasis (29.4%), schistosomiasis (17.2%), and hookworm infection (16.8%). Stool microscopy and filarial and schistosomal serologic tests gave the highest diagnostic yield. Country of origin and eosinophil count were associated with specific diagnoses. PMID:17176579

  16. Acculturation, alcohol consumption and AIDS-related risky sexual behavior among African American women.

    PubMed

    Hines, A M; Snowden, L R; Graves, K L

    1998-01-01

    The present study examined the relationship between acculturation, alcohol consumption and AIDS-related risky sexual behavior in a national probability sample of 533 African American women. Results indicated that women who were the heaviest drinkers were also the least acculturated. However, women most likely to engage in risky sexual behavior, including having multiple partners, being nonmonogamous or in a nonmonogamous relationship, and being nonmonogamous or in a nonmonogamous relationship and not using a condom consistently, were high in acculturation rather than low. Alcohol use proved related to risky sexual behavior when considered in conjunction with respondents' level of acculturation. Women at risk for contracting AIDS were not low acculturated African American women who drank heavily, but high acculturated African American women. Findings from this study extend our understanding of risk and contain implications for research and prevention efforts in the area of alcohol use and AIDS-related sexual behavior among African American women.

  17. The effect of mantle plume heads on the motion between the African and Antarctic plates in the Late Cretaceous and Early Cenozoic

    NASA Astrophysics Data System (ADS)

    Cande, S. C.; Patriat, P.

    2012-12-01

    the fracture zones (and shift in the Africa-Antarctic stage pole) around Chron 24 (53 Ma). Although both India and Africa appear to respond to the Reunion plume head around 71 Ma, it is notable that the time of India's most rapid speedup (starting around Chron 31, at 68 Ma) appears to lag the time of Africa's most rapid slowdown (Chron 32) by two or three million years, a relationship which may be an important clue as to how the Reunion plume head affects the motions of India and Africa. The sudden change in spreading direction between Africa and Antarctica as recorded on the SWIR at Chron 24 (53 Ma) is also puzzling. This change in motion is roughly synchronous with major tectonic events throughout the Atlantic region, which suggests that it was caused by the arrival of the Iceland plume head, whose onset is related to the rifting of Norway and Greenland just before Chron 24. The major Eocene slowing of India and speedup of Africa start soon after this event, around 52 Ma, suggesting that this phase of the coupled motion may also have been triggered by the arrival of the Iceland plume head. Cande, S.C. and D. R. Stegman. Indian and African plate motions driven by the push force of the Reunion plume head, Nature, v. 475, 47-52, 2011.

  18. Less drinking, yet more problems: understanding African American drinking and related problems.

    PubMed

    Zapolski, Tamika C B; Pedersen, Sarah L; McCarthy, Denis M; Smith, Gregory T

    2014-01-01

    Researchers have found that, compared to European Americans, African Americans report later initiation of drinking, lower rates of use, and lower levels of use across almost all age groups. Nevertheless, African Americans also have higher levels of alcohol problems than European Americans. After reviewing current data regarding these trends, we provide a theory to understand this apparent paradox as well as to understand variability in risk among African Americans. Certain factors appear to operate as both protective factors against heavy use and risk factors for negative consequences from use. For example, African American culture is characterized by norms against heavy alcohol use or intoxication, which protects against heavy use but also provides within-group social disapproval when use does occur. African Americans are more likely to encounter legal problems from drinking than European Americans, even at the same levels of consumption, perhaps thus resulting in reduced consumption but more problems from consumption. There appears to be one particular group of African Americans, low-income African American men, who are at the highest risk for alcoholism and related problems. We theorize that this effect is due to the complex interaction of residential discrimination, racism, age of drinking, and lack of available standard life reinforcers (e.g., stable employment and financial stability). Further empirical research will be needed to test our theories and otherwise move this important field forward. A focus on within-group variation in drinking patterns and problems is necessary. We suggest several new avenues of inquiry. PMID:23477449

  19. Less drinking, yet more problems: understanding African American drinking and related problems.

    PubMed

    Zapolski, Tamika C B; Pedersen, Sarah L; McCarthy, Denis M; Smith, Gregory T

    2014-01-01

    Researchers have found that, compared to European Americans, African Americans report later initiation of drinking, lower rates of use, and lower levels of use across almost all age groups. Nevertheless, African Americans also have higher levels of alcohol problems than European Americans. After reviewing current data regarding these trends, we provide a theory to understand this apparent paradox as well as to understand variability in risk among African Americans. Certain factors appear to operate as both protective factors against heavy use and risk factors for negative consequences from use. For example, African American culture is characterized by norms against heavy alcohol use or intoxication, which protects against heavy use but also provides within-group social disapproval when use does occur. African Americans are more likely to encounter legal problems from drinking than European Americans, even at the same levels of consumption, perhaps thus resulting in reduced consumption but more problems from consumption. There appears to be one particular group of African Americans, low-income African American men, who are at the highest risk for alcoholism and related problems. We theorize that this effect is due to the complex interaction of residential discrimination, racism, age of drinking, and lack of available standard life reinforcers (e.g., stable employment and financial stability). Further empirical research will be needed to test our theories and otherwise move this important field forward. A focus on within-group variation in drinking patterns and problems is necessary. We suggest several new avenues of inquiry.

  20. Less Drinking, Yet More Problems: Understanding African American Drinking and Related Problems

    PubMed Central

    Zapolski, Tamika C. B.; Pedersen, Sarah L.; McCarthy, Denis M.; Smith, Gregory T.

    2013-01-01

    Researchers have found that, compared to European Americans, African Americans report later initiation of drinking, lower rates of use, and lower levels of use across almost all age groups. Nevertheless, African Americans also have higher levels of alcohol problems than European Americans. After reviewing current data regarding these trends, we provide a theory to understand this apparent paradox as well as to understand variability in risk among African Americans. Certain factors appear to operate as both protective factors against heavy use and risk factors for negative consequences from use. For example, African American culture is characterized by norms against heavy alcohol use or intoxication, which protects against heavy use but which also provides within group social disapproval when use does occur. African Americans are more likely to encounter legal problems from drinking than European Americans, even at the same levels of consumption, perhaps thus resulting in reduced consumption but more problems from consumption. There appears to be one particular group of African Americans, low-income African American men, who are at the highest risk for alcoholism and related problems. We theorize that this effect is due to the complex interaction of residential discrimination, racism, age of drinking, and lack of available standard life reinforcers (e.g., stable employment and financial stability). Further empirical research will be needed to test our theories and otherwise move this important field forward. A focus on within group variation in drinking patterns and problems is necessary. We suggest several new avenues of inquiry. PMID:23477449

  1. Sociocultural Influences on Weight-Related Behaviors in African American Adolescents.

    PubMed

    Tate, Nutrena H; Davis, Jean E; Yarandi, Hossein N

    2015-12-01

    The purpose of this study was to examine the sociocultural factors related to weight behaviors in African American adolescents utilizing a social ecological approach. A descriptive correlational design included a sample of 145 African American adolescents. Perceived familial socialization, ethnic identity, physical activity, and eating behavior patterns were measured. Data were analyzed using descriptive statistics, Pearson product-moment correlations, and multiple regression equations. Perceived maternal socialization was significantly related to adolescent eating behaviors and physical activity whereas perceived paternal socialization was significantly related only to their physical activity. The adolescents' ethnic identity was not significantly related to their eating behaviors or physical activity. Health care providers who work with adolescents and their families can use the initial findings from this study to encourage healthy weight-related behaviors while reducing the obesity epidemic within the African American adolescent population in a developmentally appropriate and culturally sensitive manner.

  2. Medical mistrust is related to lower longitudinal medication adherence among African-American males with HIV.

    PubMed

    Dale, Sannisha K; Bogart, Laura M; Wagner, Glenn J; Galvan, Frank H; Klein, David J

    2016-07-01

    African-Americans living with HIV show worse health behaviors (e.g. medication adherence) and outcomes (e.g. viral suppression) than do their White counterparts. In a 6-month longitudinal study, we investigated whether medical mistrust among African-American males with HIV (214 enrolled, 140 with longitudinal data) predicted lower electronically monitored antiretroviral medication adherence. General medical mistrust (e.g. suspicion toward providers), but not racism-related mistrust (e.g. belief that providers treat African-Americans poorly due to race), predicted lower continuous medication adherence over time (b = -.08, standard error = .04, p = .03). Medical mistrust may contribute to poor health outcomes. Intervention efforts that address mistrust may improve adherence among African-Americans with HIV.

  3. Constraining the African pole of rotation

    NASA Astrophysics Data System (ADS)

    Asfaw, Laike M.

    1992-08-01

    In the absence of well defined transform faults in the East African rift system for constraining the plate kinematic reconstruction, the pole of relative motion for the African (Nubian) and Somalian plates has been determined from residual motion. If Africa and Somalia are to continue to drift apart along the East African rift system (which would then evolve into a series of ridges offset by transform faults) then incipient transform faults that may reflect the direction of relative motion should already be in place along the East African rift system. The incipient transforms along the East African rift system are characterized by shear zones, such as the Zambezi shear zone in the south and the Aswa and Hamer shear zones in the north. Some of these shear zones have been associated with recent strike-slip faulting in the NW-SE direction during periods of earthquakes. Provided that these, consistently NW-SE oriented, strike-slip movements in the shear zones give the direction of relative motion of the adjacent plates, then they can be used to constrain the position of the Africa-Somalia Euler pole. Due to the fact that identifying transform faults in the East African rift system is difficult and because the genesis of transform faults characterizing a plate boundary at an inception stage is not well known, the discussion here is limited to the northern segment of the East African rift system where shear zones are better characterized by the existing geophysical data. The characterizing features vary with latitude, indicating the complexity of the problem of the genesis of transform faults. I believe, however, that the relatively well defined intra-continental transform fault in the northern East African rift system, which is characterized by strike-slip faulting and earthquakes, constrains the pole of relative motion for the African and Somalian plates to a position near 1.5°S and 29.0°E.

  4. Dynamics of convergent plate boundaries: Insights from subduction-related serpentinite melanges from the northern edge of the Caribbean plate

    NASA Astrophysics Data System (ADS)

    García-Casco, A.

    2012-04-01

    Subduction-related rock complexes, many of them tectonic melanges, occur in the Central America-Caribbean-Andean belt. I review the lithology and P-T-t paths of HP rocks and offer interpretations and generalizations on the thermal estate of the subducting plate(s), the melange forming events, and the exhumation history of rock complexes formed in the northern branch of the Caribbean subduction zone (Cuba and nearby Guatemala and Dominican Republic; ca. 3000 km apart). These complexes contain high pressure rocks formed and exhumed at the convergent (Pacific-Atlantic) leading edge of the Caribbean plate during ca. 100 Ma (early Cretaceous-Oligocene), attesting for long lasting oceanic -followed by continental- subduction/accretion in the region. Lithologic data indicate a complex melange-forming process. In most cases, the HP rocks represent subducted MOR-related lithologies occurring as tectonic blocks within serpentinite-matrix melanges interpreted as exhumed fragments of the subduction channel(s). Most of these melanges, however, contain fragments of arc/forearc-related non metamorphic and metamorphic (low-P and high-P) sedimentary and igneous rocks. While the HP blocks of arc/forearc material indicate subduction erosion at depth, the interpretation of the LP and non-metamorphic blocks is not straight forward. Indeed, tectonic blocks of HP metamafic rocks are surrounded by antigorite-serpentinite which, in turn, is surrounded by a low-P, low-T (chrysotile-lizardite) serpentinite that makes much of the mélange. These relations indicate that the melanges represent, in fact, tectonic stacks of shallow low-T forearc serpentinite that incorporate tectonic blocks/slices of the subduction-channel (high-P, high-T serpentinite and HP metamafic blocks) and of the arc/forearc crust (low-P and non-metamorphic blocks). This picture is similar to that of HP continental margin-derived tectonic stacks containing exotic slices of antigoritite-serpentine melanges (with blocks of

  5. Smoking abstinence-related expectancies among American Indians, African Americans, and women: potential mechanisms of tobacco-related disparities.

    PubMed

    Hendricks, Peter S; Westmaas, J Lee; Ta Park, Van M; Thorne, Christopher B; Wood, Sabrina B; Baker, Majel R; Lawler, R Marsh; Webb Hooper, Monica; Delucchi, Kevin L; Hall, Sharon M

    2014-03-01

    Research has documented tobacco-related health disparities by race and gender. Prior research, however, has not examined expectancies about the smoking cessation process (i.e., abstinence-related expectancies) as potential contributors to tobacco-related disparities in special populations. This cross-sectional study compared abstinence-related expectancies between American Indian (n = 87), African American (n = 151), and White (n = 185) smokers, and between women (n = 231) and men (n = 270) smokers. Abstinence-related expectancies also were examined as mediators of race and gender relationships with motivation to quit and abstinence self efficacy. Results indicated that American Indians and African Americans were less likely than Whites to expect withdrawal effects, and more likely to expect that quitting would be unproblematic. African Americans also were less likely than Whites to expect smoking cessation interventions to be effective. Compared with men, women were more likely to expect withdrawal effects and weight gain. These expectancy differences mediated race and gender relationships with motivation to quit and abstinence self-efficacy. Findings emphasize potential mechanisms underlying tobacco-related health disparities among American Indians, African Americans, and women and suggest a number of specific approaches for targeting tobacco dependence interventions to these populations. PMID:23528192

  6. Racism-related stress, Africultural coping, and religious problem-solving among African Americans.

    PubMed

    Lewis-Coles, Ma'at E Lyris; Constantine, Madonna G

    2006-07-01

    This study explored the extent to which three types of racism-related stress (i.e., individual, institutional, and cultural) would predict the use of specific Africultural coping strategies (i.e., cognitive/emotional debriefing, spiritual-centered, collective, and ritual-centered coping) and religious problem-solving styles (i.e., self-directing, deferring, and collaborative) in a sample of 284 African American men and women. The authors found that higher institutional racism-related stress was associated with greater use of cognitive/emotional debriefing, spiritual-centered, and collective coping in African American women. Findings also indicated that higher cultural racism-related stress was predictive of lower use of self-directing religious problem-solving in African American women. Moreover, higher perceived cultural racism-related stress was related to greater use of collective coping strategies in African American men. Individual racism-related stress was not predictive of any forms of Africultural coping strategies or religious problem-solving. Implications of the findings are discussed.

  7. Relative Motion of Nubia Plate with Respect to West Africa, Congo and Kalahari Cratons

    NASA Astrophysics Data System (ADS)

    Njoroge, M. W.

    2015-12-01

    The Nubia plate is normally considered to be a rigid plate and as such used in the realization of terrestrial reference frame. Gondwana breakup plate reconstruction, the Cameroon volcanic line, seismicity, and the morphology of the Okavango rift zone (ORZ) suggest the presence of internal deformation within the Nubia plate. To test this hypothesis, six different reference frames were developed from the velocity field of three individual regions (West, Central and South), and of different combinations of them (West+Central, South+Central, and Nubia as a whole). The residual velocities with respect to these references frame help us understand the presence of the relative motion between the different regions thus the stability of the plate. To realize the reference frames, all the publicly available GPS data within the "stable" Nubia plate was processed. Given the small relative velocity, it is important to eliminate eventual biases in the analysis and to have good estimates of uncertainty of the observed velocities. For this reason, velocities were analyzed, and rate uncertainties computed using the Allan variance of rate (AVR) technique, accounting for colored noise. Although geological and geophysical studies indicate the possibility of internal deformation within Nubia, the results of this study shows that the current GPS network is not capable to identify intraplate deformation and within uncertainties Nubia is a single plate. As final note, both the color of the noise and the amplitude of the annual signal of each time series as function of latitude and climatic region were analyzed. The study shows that the noise is approximately flicker for all the good stations independently of the location. On the contrary, the amplitude of the annual signal is strongly dependent on the climate of the regions.

  8. Tectonic implications of post-30 Ma Pacific and North American relative plate motions

    USGS Publications Warehouse

    Bohannon, R.G.; Parsons, T.

    1995-01-01

    The Pacific plate moved northwest relative to North America since 42 Ma. The rapid half rate of Pacific-Farallon spreading allowed the ridge to approach the continent at about 29 Ma. Extinct spreading ridges that occur offshore along 65% of the margin document that fragments of the subducted Farallon slab became captured by the Pacific plate and assumed its motion proper to the actual subduction of the spreading ridge. This plate-capture process can be used to explain much of the post-29 Ma Cordilleran North America extension, strike slip, and the inland jump of oceanic spreading in the Gulf of California. Much of the post-29 Ma continental tectonism is the result of the strong traction imposed on the deep part of the continental crust by the gently inclined slab of subducted oceanic lithosphere as it moved to the northwest relative to the overlying continent. -from Authors

  9. Relative Motion Between the Rivera and North American Plates Determined from the Slip Directions of Earthquakes

    NASA Astrophysics Data System (ADS)

    Suárez, Gerardo; Jaramillo, Said H.; Bandy, W. L.

    2013-12-01

    So far, the direction and rate of relative motion between the Rivera and the North American plates (RIV-NAM) has been determined by the combination of two Euler poles: Rivera (RIV), with respect to Pacific (PAC), and PAC with respect to North America. Here, we estimate the relative motion of this plate pair (RIV-NAM) assuming that the horizontal projection of the direction of slip of the earthquakes occurring on the RIV-NAM boundaries reflect their relative plate motion. A catalog of earthquakes for which focal mechanisms are reported since 1976 is used in the analysis. Earthquakes were considered in the three segments of the RIV-NAM plate boundary: the subduction zone of the Rivera plate beneath the Jalisco block, the Tres Marias Escarpment and the events associated with the Tamayo Fracture Zone. The best fitting Euler pole is determined using a grid search of 64 potential poles. The slip direction predicted for each grid point is compared to the slip direction of the focal mechanisms of the earthquakes on the plate boundary. The best fitting Euler pole, determined in a root mean square sense (RMS), is located at 21.8°N, 107.6°W. A rate of rotation of 5.3°/year is estimated assuming the seismic earthquake cycle of the 1932 and 1995 great earthquakes represents a lower bound of the rate of plate motion in the subduction zone. The best fitting Euler pole shows that the subduction of the Rivera plate takes place in a direction perpendicular to the trench with a relative velocity of 4.3 cm/year, offshore Manzanillo. The rate of relative motion RIV-NAM decreases from SE to NW. North of approximately 21°N, the subduction of the Rivera plate becomes oblique to the trench and the relative velocity between the two plates decreases to an average of 1.9 cm/year. This slow rate of convergence may explain the rapid decrease of seismicity in the trench and the apparent absence of large earthquakes in this region. In the Tres Marias Escarpment, our best-fitting pole suggests

  10. Hardware-related complications following radiocarpal arthrodesis using a dorsal plate.

    PubMed

    Berling, Stephen E; Kiefhaber, Thomas R; Stern, Peter J

    2015-02-01

    Background Hardware-related complications more than 6 months after total wrist arthrodesis are rarely reported, and controversy remains around the inclusion of the middle finger carpometacarpal joint (CMCJ) in the fusion mass. Purpose To determine the frequency of hardware-related complications including plate fractures, screw fractures, and symptomatic plate/screw loosening, and to investigate whether failure to fuse the middle finger CMCJ contributed to these hardware complications. Patients and Methods A retrospective chart review was designed to identify long-term hardware-related complications following 122 wrist arthrodeses using plate fixation. Patients with at least 6 months of follow-up were reviewed to determine the number of complications, the involvement of the middle finger CMCJ, and the procedures required to address these complications. Results At a median of 2.5 years following arthrodesis (range, 6 months-19 years), 20 (16%) hardware-related complications occurred and included screw fracture (n = 12), plate loosening (n = 5), and plate fracture (n = 3). Thirteen (65%) of the hardware complications occurred after the CMCJ was not fused during the procedure. The CMCJ did not fuse after attempted arthrodesis in 6 additional wrists. Conclusions Persistent middle finger CMCJ micromotion was likely present in 19/20 wrists (95%) that experienced symptomatic hardware complications. Given the occurrence of hardware failures centering on this joint, it is our recommendation that, unless one plans for routine plate removal within a given timeframe, the middle finger CMCJ must be included in the fusion mass. Level 4 Therapeutic Case Series.

  11. Characterizing the learning styles and testing the science-related attitudes of African American middle school students: Implications for the underrepresentation of African Americans in the sciences

    NASA Astrophysics Data System (ADS)

    Perine, Donald Ray

    African Americans, Hispanics, Native Americans and women are underrepresented among the population of scientists and science teachers in the United States. Specifically, the shortage of African Americans teaching math and science at all levels of the educational process and going into the many science-related fields is manifested throughout the entire educational and career structure of our society. This shortage exists when compared to the total population of African Americans in this country, the population of African American students, and to society's demand for more math and science teachers and professionals of all races. One suggestion to address this problem is to update curricular and instructional programs to accommodate the learning styles of African Americans from elementary to graduate school. There is little in the published literature to help us understand the learning styles of African American middle school students and how they compare to African American adults who pursue science careers. There is also little published data to help inform us about the relationship between learning styles of African American middle school students and their attitudes toward science. The author used a learning styles inventory instrument to identify the learning style preferences of the African American students and adults. The preferences identified describe how African American students and African American adult science professionals prefer to function, learn, concentrate, and perform in their educational and work activities in the areas of: (a) immediate environment, (b) emotionality, (c) sociological needs, and (d) physical needs. The learning style preferences for the students and adults were not significantly different in key areas of preference. A Test of Science-Related Attitudes (TOSRA) was used to measure seven distinct science-related attitudes of the middle school students. A comparison of the profile of the mean scores for the students in this study

  12. Applying Social Psychological Models to Predicting HIV-Related Sexual Risk Behaviors Among African Americans.

    PubMed

    Cochran, Susan D; Mays, Vickie M

    1993-05-01

    Existing models of attitude-behavior relationships, including the Health Belief Model, the Theory of Reasoned Action, and the Self-Efficacy Theory, are increasingly being used by psychologists to predict human immunodeficiency virus (HIV)-related risk behaviors. The authors briefly highlight some of the difficulties that might arise in applying these models to predicting the risk behaviors of African Americans. These social psychological models tend to emphasize the importance of individualistic, direct control of behavioral choices and deemphasize factors, such as racism and poverty, particularly relevant to that segment of the African American population most at risk for HIV infection. Applications of these models without taking into account the unique issues associated with behavioral choices within the African American community may fail to capture the relevant determinants of risk behaviors.

  13. Emotion-Related Behavioral Regulation in African American Preschoolers: Social-Emotional Correlates of Teacher Perceptions

    ERIC Educational Resources Information Center

    Smith, Maureen C.

    2004-01-01

    This preliminary and exploratory study examined the correlates of 5 aspects of teacher-rated emotion-related regulation (modulation, flexibility, organization, emotion-focused coping, aggressive-coping strategies) in a sample of 36 low- to middle-income African American preschoolers. Results showed that children's empathy, emotional intensity,…

  14. Racism-Related Stress and Ethnic Identity as Determinants of African American College Students' Career Aspirations

    ERIC Educational Resources Information Center

    Tovar-Murray, Darrick; Jenifer, Ericka S.; Andrusyk, Jara; D'Angelo, Ryan; King, Tia

    2012-01-01

    Drawing primarily on the construct of psychological buffer, the purpose of this study was to explore the extent to which racism-related stress and ethnic identity are determinants of career aspirations. A total of 163 African American college students from a predominately White Midwestern university participated in the study. A moderation…

  15. Racial Identity, Social Context, and Race-Related Social Cognition in African Americans during Middle Childhood

    ERIC Educational Resources Information Center

    Rowley, Stephanie J.; Burchinal, Margaret R.; Roberts, Joanne E.; Zeisel, Susan A.

    2008-01-01

    This study examined the effect of changes in racial identity, cross-race friendships, same-race friendships, and classroom racial composition on changes in race-related social cognition from 3rd to 5th grade for 73 African American children. The goal of the study was to determine the extent to which preadolescent racial identity and social context…

  16. Relative Spousal Earnings and Marital Happiness among African American and White Women

    ERIC Educational Resources Information Center

    Furdyna, Holly E.; Tucker, M. Belinda; James, Angela D.

    2008-01-01

    The distinctive economic histories of African American and White wives suggest that involvement in household income production holds contextually situated unique meanings for these groups. Yet research has not addressed racial differences in the effects of relative earnings on marital well-being. Surveying 431 employed wives in 21 U.S. cities, we…

  17. Mechanisms of Family Impact on African American Adolescents' HIV-Related Behavior

    ERIC Educational Resources Information Center

    Kogan, Steven M.; Brody, Gene H.; Gibbons, Frederick X.; Chen, Yi-fu; Grange, Christina M.; Simons, Ronald L.; Gerrard, Meg; Cutrona, Carolyn E.

    2011-01-01

    A longitudinal model that tested mediating pathways between protective family processes and HIV-related behavior was evaluated with 195 African American youth. Three waves of data were collected when the youth were 13, 15, and 19 years old. Evidence of mediation and temporal priority were assessed for 3 constructs: academic engagement, evaluations…

  18. African American College Students' Health Behaviors and Perceptions of Related Health Issues.

    ERIC Educational Resources Information Center

    Ford, Denyce S.; Goode, Carolyn R.

    1994-01-01

    A study of African American college students compared students' health-related behaviors with their perceptions of corresponding health issues. Students had low smoking rates but higher alcohol consumption. Most students did not practice good nutrition or daily physical activity. Over half managed stress well, and three-quarters were sexually…

  19. Ring of Silence: African American Women's Experiences Related to Their Breasts and Breast Cancer Screening

    ERIC Educational Resources Information Center

    Thomas, Eileen

    2006-01-01

    The purpose of this study was to explore women's memories and feelings concerning their breasts and breast cancer screening experiences in relation to their current breast cancer screening behaviors. Twelve African American women shared stories that were generated in written narratives and individual interviews. Two core themes emerged from the…

  20. African American Career Aspirations: Examining the Relative Influence of Internalized Racism

    ERIC Educational Resources Information Center

    Brown, Danice L.; Segrist, Daniel

    2016-01-01

    The present study examined the relative influence of aspects of internalized racism on the career aspirations of a sample of African American adults. Participants (N = 315), ranging in age from 18 to 62 years, completed measures of internalized racism and career aspirations online. A hierarchical multiple regression analysis was conducted to…

  1. Plate motion

    SciTech Connect

    Gordon, R.G. )

    1991-01-01

    The motion of tectonic plates on the earth is characterized in a critical review of U.S. research from the period 1987-1990. Topics addressed include the NUVEL-1 global model of current plate motions, diffuse plate boundaries and the oceanic lithosphere, the relation between plate motions and distributed deformations, accelerations and the steadiness of plate motions, the distribution of current Pacific-North America motion across western North America and its margin, plate reconstructions and their uncertainties, hotspots, and plate dynamics. A comprehensive bibliography is provided. 126 refs.

  2. Relative and Absolute Plate Motions, Mantle Plumes and Volcanism in the Arctic region

    NASA Astrophysics Data System (ADS)

    Gaina, C.; Torsvik, T. H.

    2012-04-01

    Seafloor spreading in the North Atlantic ocean from Mesozoic until present day involved relative motion between three major tectonic plates: North America, Greenland and Eurasia and a number of microplates. Relative motions between these tectonic plates and movement of northern Pacific terranes since the Jurassic led to the development of the Arctic region as we know it today. Studying the connection between the two realms involve good knowledge of the development of the North Atlantic and Arctic margins and oceanic basins and ideally, model uncertainties. Here we review the kinematics of North Atlantic and asses the implications of different models for locating the plate boundaries in the Arctic. One set of models implies extension before opening of the Eurasia basin and we postulate that this was accommodated in the proximity of Alpha- Mendeleev Ridge. The origin of (mainly) Cretaceous large igneous activity in the central Arctic (the Alpha Mendeleev Ridge) and in the proximity of rifted margins, the so-called HALIP, is still debated. New models of global plate circuits and the connection with deep mantle are used to re-evaluate a possible link between the Arctic volcanism and mantle plumes.

  3. Two African viruses serologically and morphologically related to rabies virus.

    PubMed

    Shope, R E; Murphy, F A; Harrison, A K; Causey, O R; Kemp, G E; Simpson, D I; Moore, D L

    1970-11-01

    Lagos bat virus and an isolate from shrews (IbAn 27377), both from Nigeria, were found to be bullet-shaped and to mature intracytoplasmically in association with a distinct matrix. They were related to, but readily distinguishable from, rabies virus and each other by complement fixation and neutralization tests. The three viruses, including rabies, form a subgrouping within the rhabdoviruses. PMID:5530013

  4. The role of the African-American physician in reducing traffic-related injury and death among African Americans: consensus report of the National Medical Association.

    PubMed Central

    Daniels, Fernando; Moore, Wayne; Conti, Christopher; Norville Perez, Lucille C.; Gaines, Beverly M.; Hood, Rodney G.; Swain, Ian J. J.; Williams, Rudolph; Burgess, Chaka T.

    2002-01-01

    ISSUE: Traffic-related injuries and fatalities disproportionately affect the African American community. These high rates of traffic-related death and injury among African Americans manifest in multiple areas of traffic safety, including: Failure to use seat belts and child restraints. High incidence of alcohol-impaired driving. Failure to follow child passenger and seat belt safety laws and recommendations. High rates of pedestrian accidents, ofen brought on by impairments of drivers and/or pedestrians. Research indicates that national public information campaigns, with general messages only slightly modified for African American audiences, have not been culturally appropriate or effective in changing traffic safety behavior. In addition, traditional distribution mechanisms for these messages have not effectively reached the target population. Evidence suggests that in the African American community, there is a pervasive lack of knowledge of the devastating impact of traffic-related accidents on the overall health status of the community. This lack of information has resulted in a tragic cycle, in which parents fail to model safe operation of motor vehicles, and generation after generation copy this behavior, increasing the community's vulnerability to serious injuries and untimely deaths. This trend toward improper traffic safety habits among African Americans persists despite federal, state and local laws to enforce and promote sound traffic safety practices. OBJECTIVE: To study the existence of disparities in traffic-related injury and death among African Americans and to determine what kinds of traffic safety messages and campaigns will be effective in encouraging African Americans to respond to safety laws in sufficient numbers to reduce the disproportionately high rate of injury and death. Traffic safety issues were examined to effectively recommend policy, address barriers, best practices, and intervention strategies for the National Medical Association

  5. Knowledge, Beliefs and Behaviours Related to STD Risk, Prevention, and Screening among a Sample of African American Men and Women

    ERIC Educational Resources Information Center

    Uhrig, Jennifer D.; Friedman, Allison; Poehlman, Jon; Scales, Monica; Forsythe, Ann

    2014-01-01

    Objective: Current data on sexually transmitted disease (STD) among African Americans show significant racial/ethnic disparities. The purpose of this study was to explore knowledge, attitudes, beliefs, and behaviours related to STD risk, prevention, and testing among African American adults to help inform the development of a health communication…

  6. Cannabis Use Frequency and Use-Related Impairment among African American and White Users: The Impact of Cannabis Use Motives

    PubMed Central

    Shah, Sonia M.; Dean, Kimberlye E.; Zvolensky, Michael J.

    2015-01-01

    Objectives Cannabis use motives are differentially related to cannabis-related impairment and coping motives appear to have the strongest relation to use-related impairment. However, it is currently unknown whether African American individuals differ from White persons in reasons for using cannabis. It is also unknown whether motives’ relations to cannabis use and related impairment vary as a function of race. The present study examined the role of race on cannabis use motives and tested whether motives’ relations with cannabis use and related impairment differed by race. Design The sample consisted of 111 (67.6% non-Hispanic White, 32.4% African American) current cannabis-using adults. Results African American participants did not significantly differ from White participants on cannabis use frequency or use-related impairment. African American participants endorsed more social motives than White participants. Race interacted with social, coping, and conformity motives to predict cannabis-related impairment such that these motives were positively related to cannabis impairment among African American, but not White, participants. Conclusion Although African American and White participants do not differ in their cannabis use frequency or cannabis-related impairment, they appear to use cannabis for different reasons. Further, conformity, coping, and social motives were differentially associated with cannabis-related impairment as a function of race. Findings suggest motives for cannabis use should be contexualized in the context of race. PMID:26264291

  7. Relations between earthquake activities and configuration of the subducting Pacific plate interface along the Japan Trench

    NASA Astrophysics Data System (ADS)

    Yamada, T.; Nakahigashi, K.; Kuwano, A.; Machida, Y.; Mochizuki, K.; Shinohara, M.; Kanazawa, T.; Hino, R.; Takanami, T.

    2010-12-01

    We performed passive and active seismic experiments using 189 ocean bottom seismometers in the land slope region along the Japan Trench. The accuracy of locations for more than 5000 earthquakes along the Japan Trench were drastically improved, and we deduced the configuration of the subducting Pacific plate from the distribution while considering others such as the seismic refraction data and previous studies. These provide us a window of opportunity to compare configuration of the subducting plate and seismic activity. Our plate model shows that the dip angle of the subducting plate is small from the trench to turning points whose depth of the interface is approximately 30 km although it has lateral variation along the trench axis and its pattern seems to be correspondent with seismic boundaries. Seismicity is not much in the region, however the rate has zone characters. The dip angle increase abruptly at the turning points, and they correspond to edges of the rapture zones of almost all large earthquakes in recent years. The seismicity are relatively high in adjacent areas of the asperities including the turning points and both interplate and intraplate regions. In contrast, there are few thrust-type microearthquakes in the asperities. We can also see the double seismic planes, and one of the lower planes seems to come through the trench region and connect the seismicity beneath the outer rise.

  8. Permian and Pennsylvanian tectonic events in eastern California in relation to major plate motions

    SciTech Connect

    Stevens, C.H.; Sedlock, R. ); Stone, P. )

    1993-04-01

    Northwest-trending basins cutting across older northeast-trending facies belts in eastern California opened by Middle Pennsylvanian time and continued to develop and expand into the Early Permian. Basin development was accompanied by east-vergent thrust-faulting in the Early Permian and was followed by development of northeast-trending folds and regional uplift in middle and Late Permian time. These events have been considered products of long-tern sinistral truncation of the western North American continental margin. Later, in the Late Permian, extensional faulting created small northeast-trending basins in which deposition of terrestrial and shallow-marine rocks occurred. The author consider all late Paleozoic tectonism in eastern California to have been driven by plate interactions along the western margin of North America and to be only indirectly related to the late Paleozoic collision between North America and Gondwana. They propose that the truncated part of North America was part of the Paleo-pacific plate. In Nevada the margin of this plate, along which the Havallah assemblage eventually was emplaced, was convergent, but in California the margin bent sharply and became transform. This fault continued as the Mojave-Sonora mega-shear into Mexico where the oceanic part of the Paleopacific plate was subducted under Gondwana, forming an extensive arc now represented by rocks in S. America.

  9. Impact of disaster-related mortality on gross domestic product in the WHO African Region

    PubMed Central

    Kirigia, Joses M; Sambo, Luis G; Aldis, William; Mwabu, Germano M

    2004-01-01

    Background Disaster-related mortality is a growing public health concern in the African Region. These deaths are hypothesized to have a significantly negative effect on per capita gross domestic product (GDP). The objective of this study was to estimate the loss in GDP attributable to natural and technological disaster-related mortality in the WHO African Region. Methods The impact of disaster-related mortality on GDP was estimated using double-log econometric model and cross-sectional data on various Member States in the WHO African Region. The analysis was based on 45 of the 46 countries in the Region. The data was obtained from various UNDP and World Bank publications. Results The coefficients for capital (K), educational enrolment (EN), life expectancy (LE) and exports (X) had a positive sign; while imports (M) and disaster mortality (DS) were found to impact negatively on GDP. The above-mentioned explanatory variables were found to have a statistically significant effect on GDP at 5% level in a t-distribution test. Disaster mortality of a single person was found to reduce GDP by US$0.01828. Conclusions We have demonstrated that disaster-related mortality has a significant negative effect on GDP. Thus, as policy-makers strive to increase GDP through capital investment, export promotion and increased educational enrolment, they should always keep in mind that investments made in the strengthening of national capacity to mitigate the effects of national disasters expeditiously and effectively will yield significant economic returns. PMID:15113453

  10. Emotional adjustment and distressed interpersonal relations among low-income African American mothers: moderating effects of demanding kin relations.

    PubMed

    Taylor, Ronald D; Budescu, Mia

    2013-01-01

    Association of mothers' emotional adjustment and negative kin relations with distressed interpersonal relations was examined. Among 115 low-income African American mothers, relationship of depressive symptoms, self-esteem, and demanding kin relations with psychological control and stressful interpersonal relations was assessed. Depressive symptoms and demanding kin relations were positively associated with mothers' use of psychological control in parenting. Interaction of self-esteem with demanding kin relations revealed that self-esteem was negatively associated with psychological control for mothers with high-demanding kin relations but not for mothers with low-demanding kin relations. Mothers' depressive symptoms and demanding kin relations were positively associated with their stressful interpersonal relations. Findings were discussed in terms of the need for research on the beneficial and detrimental aspects of families' social network. PMID:23356357

  11. Emotional adjustment and distressed interpersonal relations among low-income African American mothers: moderating effects of demanding kin relations.

    PubMed

    Taylor, Ronald D; Budescu, Mia

    2013-01-01

    Association of mothers' emotional adjustment and negative kin relations with distressed interpersonal relations was examined. Among 115 low-income African American mothers, relationship of depressive symptoms, self-esteem, and demanding kin relations with psychological control and stressful interpersonal relations was assessed. Depressive symptoms and demanding kin relations were positively associated with mothers' use of psychological control in parenting. Interaction of self-esteem with demanding kin relations revealed that self-esteem was negatively associated with psychological control for mothers with high-demanding kin relations but not for mothers with low-demanding kin relations. Mothers' depressive symptoms and demanding kin relations were positively associated with their stressful interpersonal relations. Findings were discussed in terms of the need for research on the beneficial and detrimental aspects of families' social network.

  12. HIV-related stigma among African, Caribbean, and Black youth in Windsor, Ontario.

    PubMed

    Mihan, Robert; Kerr, Jelani; Maticka-Tyndale, Eleanor

    2016-01-01

    HIV-related stigma has been shown to undermine prevention, care, treatment, and the well-being of people living with HIV. A disproportion burden of HIV infection, as well as elevated levels of HIV-related stigma, is evidenced in sub-Saharan African (SSA) and African-diasporic populations. This study explores factors that influence HIV-related stigma among 16- to 25-year-old youth residing in a Canadian city who identify as African, Caribbean, or Black. Stigma, as rooted in cultural norms and beliefs and related social institutions, combined with insights from research on stigma in SSA and African-diasporic populations, guided the development of a path analytic structural equation model predicting levels of HIV-related stigmatizing attitudes. The model was tested using survey responses of 510 youth to estimate the direct and indirect influences of ethno-religious identity, religious service attendance, time in Canada, HIV/AIDS knowledge, HIV-testing history, sexual health service contact, and gender on HIV-related stigma. Statistically significant negative associations were found between levels of stigma and knowledge and HIV-testing history. Ethno-religious identity and gender had both direct and indirect effects on stigma. African-Muslim participants had higher levels of stigma, lower knowledge, and were less likely to have been tested for HIV infection than other ethno-religious groups. Male participants had higher levels of stigma and lower knowledge than women. Time in Canada had only indirect effects on stigma, with participants in Canada for longer periods having higher knowledge and less likely to have been tested than more recent arrivals. While the strength of the effect of knowledge on stigmatizing attitudes in this research is consistent with other research on stigma and evaluations of stigma-reduction programs, the path analytic results provide additional information about how knowledge and HIV-testing function as mediators of non

  13. North American-Pacific relative plate motion in southern California from interferometry

    NASA Technical Reports Server (NTRS)

    Lyzenga, G. A.; Golombek, M. P.

    1986-01-01

    VLBI measurements of baselines crossing the San Andreas fault zone in southern California have provided observational constraints on rates of elastic tectonic strain accumulation. The single site located near this fault (the JPL site) moves in a direction concordant with the Pacific plate motion vector but at approximately half the net rate relative to North America. This motion agrees approximately in amount with geologically determined displacement rates on the San Andreas fault alone but not with the local strike of the fault. When considered together with complementary geodetic data, these results suggest a complex relation between the short-term accumulation of elastic strain and its permanent accommodation on existing faults.

  14. Everyday discrimination, diabetes-related distress, and depressive symptoms among African Americans and Latinos with diabetes.

    PubMed

    LeBron, Alana M W; Valerio, Melissa A; Kieffer, Edith; Sinco, Brandy; Rosland, Ann-Marie; Hawkins, Jaclynn; Espitia, Nicolaus; Palmisano, Gloria; Spencer, Michael

    2014-12-01

    It is not known how discrimination might affect diabetes-related distress (DRD), an important correlate of diabetes outcomes. We examined correlates of discrimination and the influence of discrimination on DRD and depressive symptoms (DS) for African Americans and Latinos with type 2 diabetes. We analyzed survey data (n = 157) collected at enrollment into a diabetes management intervention. Using multiple linear regression, we examined correlates of discrimination and the association between discrimination and DRD and DS. Discrimination was significantly associated with higher DRD for Latinos (b 1.58, 95% CI 1.08, 2.31, p < 0.05), but not significant for African Americans (b 0.96, 95% CI 0.59, 1.57). Discrimination was marginally significantly associated with more DS for Latinos (b 1.43, 95% CI 0.97, 2.12, p < 0.10), but not significant for African Americans (b 1.21, 95% CI 0.87, 1.70). These findings suggest the need to address stressors unique to racial/ethnic minorities to improve diabetes-related outcomes.

  15. The timing of Mediterranean sapropel deposition relative to insolation, sea-level and African monsoon changes

    NASA Astrophysics Data System (ADS)

    Grant, Katharine; Grimm, Rosina; Mikolajewicz, Uwe; Marino, Gianluca; Rohling, Eelco

    2016-04-01

    The periodic deposition of organic rich layers or 'sapropels' in eastern Mediterranean sediments can be linked to orbital-driven changes in the strength and location of (east) African monsoon precipitation. Sapropels are therefore an extremely useful tool for establishing orbital chronologies, and for providing insights about African monsoon variability on long timescales. However, the link between sapropel formation, insolation variations, and African monsoon 'maxima' is not straightforward because other processes (notably, sea-level rise) may have contributed to their deposition, and because there are uncertainties about monsoon-sapropel phase relationships. For example, different phasings are observed between Holocene and early Pleistocene sapropels, and between proxy records and model simulations. To address these issues, we have established geochemical and ice-volume-corrected planktonic foraminiferal stable isotope records for sapropels S1, S3, S4, and S5 in core LC21 from the southern Aegean Sea. The records have a radiometrically constrained chronology that has already been synchronised with the Red Sea relative sea-level record, and this allows us to examine in detail the timing of sapropel deposition relative to insolation, sea-level, and African monsoon changes. Our records suggest that the onset of sapropel deposition and monsoon run-off was near synchronous, yet insolation-sapropel/monsoon phasings varied, whereby monsoon/sapropel onset was relatively delayed (with respect to insolation maxima) after glacial terminations. We suggest that large meltwater discharges into the North Atlantic modified the timing of sapropel deposition by delaying the timing of peak African monsoon run-off. Hence, the previous assumption of a systematic 3-kyr lag between insolation maxima and sapropel midpoints may lead to overestimated insolation-sapropel phasings. We also surmise that both monsoon run-off and sea-level rise were important buoyancy-forcing mechanisms for

  16. Related strains of African swine fever virus with different virulence: genome comparison and analysis.

    PubMed

    Portugal, Raquel; Coelho, João; Höper, Dirk; Little, Nicole S; Smithson, Chad; Upton, Chris; Martins, Carlos; Leitão, Alexandre; Keil, Günther M

    2015-02-01

    Two strains of African swine fever virus (ASFV), the high-virulence Lisboa60 (L60) and the low-virulence NH/P68 (NHV), which have previously been used in effective immunization/protection studies, were sequenced. Both were isolated in Portugal during the 11-year period after the introduction of ASFV to the European Continent in 1957. The predicted proteins coded by both strains were compared, and where differences were found these were also compared to other strains of known virulence. This highlighted several genes with significant alterations in low-virulence strains of ASFV that may constitute virulence factors, several of which are still uncharacterized regarding their function. Phylogenetic analysis grouped L60 and NHV closest to other P72 genotype I ASFV strains from Europe and West Africa, consistent with the assumed West African origin of all European strains. Interestingly, a relatively lower genomic identity exists between L60 and NHV, both isolated in a similar geographical location 8 years apart, than with other European and west African strains isolated subsequently and in more distant locations. This may reflect the intensive passage in tissue culture, during the early 1960s, of a Portuguese isolate to obtain an attenuated vaccine, which may have led to NHV. This study contributes to a better understanding of the evolution of ASFV, and defines additional potential virulence genes for future studies of pathogenesis towards the development of effective vaccines.

  17. New Constraints on Baja California-North America Relative Plate Motion Since 11 Ma

    NASA Astrophysics Data System (ADS)

    Bennett, S. E.; Skinner, L. A.; Darin, M. H.; Umhoefer, P. J.; Oskin, M. E.; Dorsey, R. J.

    2013-12-01

    Tectonic reconstructions of the Pacific-North America (PAC-NAM) plate boundary across the Gulf of California and Salton Trough (GCAST) constrain the controversial magnitude of Baja California microplate-North America (BCM-NAM) relative motion since middle Miocene time. We use estimates of total PAC-NAM relative dextral-oblique motion from the updated global plate-circuit model (Atwater and Stock, 2013; GSA Cordilleran Mtg) to resolve the proportion of this motion on faults east of the BCM. Modern GPS studies and offset of late Miocene cross-gulf geologic tie points both suggest that BCM has never been completely coupled to the Pacific plate. Thus, our preferred GCAST reconstruction uses 93% BCM-PAC coupling from the present back to 6 Ma. We assume BCM-PAC coupling of 60% between 6 and 7 Ma, and 25% between 7 and 11 Ma, to avoid unacceptable overlap of continental crustal blocks between Baja California and the Sierra Madre Occidental (on stable NAM). Using these coupling ratios and PAC-NAM stage Euler poles, we determine the azimuth and velocity of individual points on the BCM in 1 million year increments back to 11 Ma. This procedure accounts for minor clockwise rotation of BCM that occurred during oblique rifting, and shows how total BCM-NAM relative motion increases from north to south due to greater distance from the Euler pole. Finer-scale restoration of tectonic blocks along significant (>1 km offset) faults, across extensional (e.g. pull-apart and half-graben) basins, and by vertical-axis rotation is constrained by local geologic and marine-geophysical datasets and accomplished via the open-source Tectonic Reconstruct ArcGIS tool. We find that restoration across the Gulf of California completely closes marine basins and their terrestrial predecessors between 6 and 9 Ma. Latest Miocene opening of these basins was coincident with a ~10° clockwise azimuthal change from 8 to 6 Ma in PAC-NAM relative motion, as revealed by the global plate circuit model. The

  18. The timing of Mediterranean sapropel deposition relative to insolation, sea-level and African monsoon changes

    NASA Astrophysics Data System (ADS)

    Grant, K. M.; Grimm, R.; Mikolajewicz, U.; Marino, G.; Ziegler, M.; Rohling, E. J.

    2016-05-01

    The Mediterranean basin is sensitive to global sea-level changes and African monsoon variability on orbital timescales. Both of these processes are thought to be important to the deposition of organic-rich sediment layers or 'sapropels' throughout the eastern Mediterranean, yet their relative influences remain ambiguous. A related issue is that an assumed 3-kyr lag between boreal insolation maxima and sapropel mid-points remains to be tested. Here we present new geochemical and ice-volume-corrected planktonic foraminiferal stable isotope records for sapropels S1 (Holocene), S3, S4, and S5 (Marine Isotope Stage 5) in core LC21 from the southern Aegean Sea. The records have a radiometrically constrained chronology that has already been synchronised with the Red Sea relative sea-level record, and this allows detailed examination of the timing of sapropel deposition relative to insolation, sea-level, and African monsoon changes. We find that sapropel onset was near-synchronous with monsoon run-off into the eastern Mediterranean, but that insolation-sapropel/monsoon phasings were not systematic through the last glacial cycle. These latter phasings instead appear to relate to sea-level changes. We propose that persistent meltwater discharges into the North Atlantic (e.g., at glacial terminations) modified the timing of sapropel deposition by delaying the timing of peak African monsoon run-off. These observations may reconcile apparent model-data offsets with respect to the orbital pacing of the African monsoon. Our observations also imply that the previous assumption of a systematic 3-kyr lag between insolation maxima and sapropel midpoints may lead to overestimated insolation-sapropel phasings. Finally, we surmise that both sea-level rise and monsoon run-off contributed to surface-water buoyancy changes at times of sapropel deposition, and their relative influences differed per sapropel case, depending on their magnitudes. Sea-level rise was clearly important for

  19. An Examination of Color-Blind Racism and Race-Related Stress among African American Undergraduate Students

    ERIC Educational Resources Information Center

    Coleman, M. Nicole; Chapman, Stephanie; Wang, David C.

    2013-01-01

    This study examined the role of color-blind racial ideology among a sample of 152 African American undergraduate students in relation to race-related stress. We hypothesized that those who endorsed relatively higher color-blind racial attitudes would experience greater race-related stress because experiences with racism would be interpreted as…

  20. The 2011 Tohoku-oki Earthquake related to a large velocity gradient within the Pacific plate

    NASA Astrophysics Data System (ADS)

    Matsubara, Makoto; Obara, Kazushige

    2015-04-01

    rays from the hypocenter around the coseismic region of the Tohoku-oki earthquake take off downward and pass through the Pacific plate. The landward low-V zone with a large anomaly corresponds to the western edge of the coseismic slip zone of the 2011 Tohoku-oki earthquake. The initial break point (hypocenter) is associated with the edge of a slightly low-V and low-Vp/Vs zone corresponding to the boundary of the low- and high-V zone. The trenchward low-V and low-Vp/Vs zone extending southwestward from the hypocenter may indicate the existence of a subducted seamount. The high-V zone and low-Vp/Vs zone might have accumulated the strain and resulted in the huge coseismic slip zone of the 2011 Tohoku earthquake. The low-V and low-Vp/Vs zone is a slight fluctuation within the high-V zone and might have acted as the initial break point of the 2011 Tohoku earthquake. Reference Matsubara, M. and K. Obara (2011) The 2011 Off the Pacific Coast of Tohoku earthquake related to a strong velocity gradient with the Pacific plate, Earth Planets Space, 63, 663-667. Okada, Y., K. Kasahara, S. Hori, K. Obara, S. Sekiguchi, H. Fujiwara, and A. Yamamoto (2004) Recent progress of seismic observation networks in Japan-Hi-net, F-net, K-NET and KiK-net, Research News Earth Planets Space, 56, xv-xxviii.

  1. Oceanic Remnants In The Caribbean Plate: Origin And Loss Of Related LIPs.

    NASA Astrophysics Data System (ADS)

    Giunta, G.

    2005-12-01

    The modern Caribbean Plate is an independent lithospheric entity, occupying more than 4 Mkm2 and consisting of the remnants of little deformed Cretaceous oceanic plateau of the Colombia and Venezuela Basins (almost 1 Mkm2) and the Palaeozoic-Mesozoic Chortis continental block (about 700,000 km2), both bounded by deformed marginal belts. The northern (Guatemala and Greater Antilles) and the southern (northern Venezuela) plate margins are marked by collisional zones, whereas the western (Central America Isthmus) and the eastern (Lesser Antilles) margins are represented by convergent boundaries and their magmatic arcs, all involving ophiolitic terranes. The evolutionary history of the Caribbean Plate since the Jurassic-Early Cretaceous encompasses plume, accretionary, and collisional tectonics, the evidence of which has been recorded in the oceanic remnants of lost LIPs, as revealed in: i) the MORB to OIB thickened crust of the oceanic plateau, including its un-deformed or little deformed main portion, and scattered deformed tectonic units; ii) ophiolitic tectonic units of MORB affinity and the rock blocks in ophiolitic melanges; iii) intra-oceanic, supra subduction magmatic sequences with IAT and CA affinities. The Mesozoic oceanic LIPs, from which the remnants of the Caribbean Plate have been derived, have been poorly preserved during various episodes of the intra-oceanic convergence, either those related to the original proto-Caribbean oceanic realm or those connected with two eo-Caribbean stages of subduction. The trapped oceanic plateau of the Colombia and Venezuela Basins is likely to be an unknown portion of a bigger crustal element of a LIP, similar to the Ontong-Java plateau. The Jurassic-Early Cretaceous proto-Caribbean oceanic domain consists of oceanic crust generated at multiple spreading centres; during the Cretaceous, part of this crust was thickened to form an oceanic plateau with MORB and OIB affinities. At the same time, both South and North American

  2. Appropriateness of no-fault compensation for research-related injuries from an African perspective: an appeal for action by African countries.

    PubMed

    Kamalo, Patrick Dongosolo; Manda-Taylor, Lucinda; Rennie, Stuart

    2016-08-01

    Compensation for research-related injuries (RRIs) remains a challenge in the current environment of global collaborative biomedical research as exemplified by the continued reluctance of the US government, a major player in international biomedical research, to enact regulation for mandatory compensation for RRIs. This stance is in stark contrast to the mandatory compensation policies adopted by other democracies like the European Union (EU) countries. These positions taken by the USA and the EU create a nexus of confusion when research is exported to low-income and middle-income countries which have no laws guiding compensation for RRIs. In this paper, we begin by exploring the background to policies concerning RRIs, how they reflect on the traditional dispute resolution mechanisms in African societies, and how this compares with the no-fault compensation model. We then explore the underlying African ethical framework of Ubuntu in the sub-Saharan region, guiding traditional practices of dispute resolution and compensation, and how this framework can help to form the moral justification for no-fault compensation as the preferred compensation model for RRIs for African countries. Finally, we call upon countries in the African Union (AU), to adopt a no-fault policy for compensation of RRIs, and enact it into a regulatory requirement for insurance-based no-fault compensation for biomedical research, which will then be enforced by member states of the AU. PMID:27259545

  3. Appropriateness of no-fault compensation for research-related injuries from an African perspective: an appeal for action by African countries.

    PubMed

    Kamalo, Patrick Dongosolo; Manda-Taylor, Lucinda; Rennie, Stuart

    2016-08-01

    Compensation for research-related injuries (RRIs) remains a challenge in the current environment of global collaborative biomedical research as exemplified by the continued reluctance of the US government, a major player in international biomedical research, to enact regulation for mandatory compensation for RRIs. This stance is in stark contrast to the mandatory compensation policies adopted by other democracies like the European Union (EU) countries. These positions taken by the USA and the EU create a nexus of confusion when research is exported to low-income and middle-income countries which have no laws guiding compensation for RRIs. In this paper, we begin by exploring the background to policies concerning RRIs, how they reflect on the traditional dispute resolution mechanisms in African societies, and how this compares with the no-fault compensation model. We then explore the underlying African ethical framework of Ubuntu in the sub-Saharan region, guiding traditional practices of dispute resolution and compensation, and how this framework can help to form the moral justification for no-fault compensation as the preferred compensation model for RRIs for African countries. Finally, we call upon countries in the African Union (AU), to adopt a no-fault policy for compensation of RRIs, and enact it into a regulatory requirement for insurance-based no-fault compensation for biomedical research, which will then be enforced by member states of the AU.

  4. Stigma as a Barrier to HIV-Related Activities Among African-American Churches in South Carolina.

    PubMed

    Pryor, John B; Gaddist, Bambi; Johnson-Arnold, Letitia

    2015-01-01

    South Carolina has one of the highest HIV/AIDS prevalence rates in the United States. More than 70% of those infected are African American. Traditionally, Black churches have been one of the primary sources of health outreach programs in Southern African-American communities. In this research, we explored the role of HIV-related stigma as a barrier to the acceptance of HIV-related activities in Black churches. A survey of African-American adults in South Carolina found that the overall level of stigma associated with HIV/AIDS was comparable to what has been found in a national probability sample of people in the United States. Consistent with the stigma-as-barrier hypothesis, the degree to which survey respondents endorsed HIV-related stigma was related to less positive attitudes concerning the involvement of Black churches in HIV-related activities.

  5. Past Plate Motions and The Evolution of Earth's Lower Mantle: Relating LLSVPs and Plume Distribution

    NASA Astrophysics Data System (ADS)

    Bull, A. L.; Torsvik, T. H.; Shephard, G. E.

    2015-12-01

    Seismic tomography elucidates broad, low shear-wave velocity structures in the lower mantle beneath Africa and the central Pacific with uncertain physical and compositional origins. The anomalously slow areas, which cover nearly 50% of the core-mantle boundary, are often referred to as Large Low Shear Velocity Provinces (LLSVPs) due to the reduced velocity of seismic waves passing through them. Several hypotheses have arisen to explain the LLSVPs in the context of large-scale mantle convection. One end-member scenario infers a spatial correlation between LLSVP margins at depth and the reconstructed surface eruption sites of hotspots, kimberlites, and Large Igneous Provinces. Such a correlation has been explained by the preferential triggering of plumes at LLSVP margins by impingement of the subducting lithosphere upon the lower thermal boundary layer at the interface between ambient mantle and the higher density structures. This scenario propounds that Earth's plate motion history plays a controlling role in plume development, and that the location, geometry and morphology of plumes may be influenced by the movement of subducting slabs. Here, we investigate what is necessary to create such a pattern of plume distribution in relation to LLSVPs. We consider what effect past plate motions may have had on the evolution of Earth's lower mantle, and discuss the development of mantle plumes in terms of subduction dynamics. We integrate plate tectonic histories and numerical models of mantle convection to investigate the role that subduction history plays in the development and evolution of plumes in the presence of LLSVPs. To test whether an interaction exists between the surface location of subduction and plume eruption sites, and if so, to what degree over time, we apply varying shifts to the absolute reference frame of the plate reconstruction. With this method, we are able to change the location of subduction at the surface and thus the global flow field. This in turn

  6. Cretaceous Pacific plate movement beneath SE China: Evidence from episodic volcanism and related intrusions

    NASA Astrophysics Data System (ADS)

    Liu, Lei; Xu, Xisheng; Xia, Yan

    2014-02-01

    Extensive Late Mesozoic igneous rocks in SE China have been widely considered to be generated under the paleo-Pacific tectonic regime, the plate subduction model, however, remains controversial. This study focuses on the Cretaceous volcanic rocks in northwestern Zhejiang Province. Zircon U-Pb age determination indicates that Cretaceous volcanism in northwestern Zhejiang took place at three episodes of 140-130, 130-127 and 123-118 Ma, in good agreement with the coeval lower volcanic series in southeastern Zhejiang, but lacking the episode at 110-88 Ma corresponding to the upper volcanic series. The Cretaceous volcanic rocks in Zhejiang therefore show an oceanward younging trend. In situ zircon Hf isotope analyses of three episodes of volcanics yield ɛHf(t) values of - 11.2 to - 8.7, -4.8 to - 2.4 and - 4.4 to + 2.2, respectively. The entire sequences display typical isotopic features of magma mixing, implying progressive involvement of juvenile component. Based on systematical researches on the Cretaceous volcanic rocks and a series of granitoid plutons in Zhejiang, it is also identified that the juvenile component involvement gradually occurred from the inland to the coast under an enhanced lithospheric extensional tectonic setting. All the observations in this study indicate the northwestward paleo-Pacific plate subduction with episodic slab rollback which triggered the arc system to retreat towards the Pacific Ocean, rather than the southwestward subduction related to the ridge subduction along the Lower Yangtze River belt.

  7. New and simple plate test for screening relative transfructosylation activity of fungi.

    PubMed

    Dominguez, Ana; Santos, Isabel M; Teixeira, José A; Lima, Nelson

    2006-09-01

    Several microorganisms are reported to have transfructosylation activity due to fructosyltransferase and/or fructofuranosidase activities. However, the search for other fungi with higher transfructosylation activity remains a challenge. So, a presumptive and indirect colorimetric plate assay for the evaluation of transfructosylation activity in fungi was developed which involved the simultaneous determination in the same plate of glucose and fructose released from sucrose. The method entailed the (a) glucose oxidase-peroxidase coupled reaction using phenol and 4-aminoantipyrine for determination of glucose; and (b) fructose dehydrogenase oxidation in the presence of a tetrazolium salt for determination of fructose. The presence of enzymes with transfructosylation activity was identified by the formation of pink (presence of glucose) and blue (presence of fructose) halos around the fungal colony. In conclusion, the results showed that the method is suitable for screening a large number of fungi due to its simplicity, reproducibility and rapidity and also gives a relative quantitative idea of the transfructosylation activity of different fungi species. PMID:17196028

  8. Being selective at the plate: processing dependence between perceptual variables relates to hitting goals and performance.

    PubMed

    Gray, Rob

    2013-08-01

    Performance of a skill that involves acting on a goal object (e.g., a ball to be hit) can influence one's judgment of the size and speed of that object. The present study examined how these action-specific effects are affected when the goal of the actor is varied and they are free to choose between alternative actions. In Experiment 1, expert baseball players were asked to perform three different directional hitting tasks in a batting simulation and make interleaved perceptual judgments about three ball parameters (speed, plate crossing location, and size). Perceived ball size was largest (and perceived speed was slowest) when the ball crossing location was optimal for the particular hitting task the batter was performing (e.g., an "outside" pitch for opposite-field hitting). The magnitude of processing dependency between variables (speed vs. location and size vs. location) was positively correlated with batting performance. In Experiment 2, the action-specific effects observed in Experiment 1 were mimicked by systematically changing the ball diameter in the simulation as a function of plate crossing location. The number of swing initiations was greater when ball size was larger, and batters were more successful in the hitting task for which the larger pitches were optimal (e.g., greater number of pull hits than opposite-field hits when "inside" pitches were larger). These findings suggest attentional accentuation of goal-relevant targets underlies action-related changes in perception and are consistent with an action selection role for these effects.

  9. Predictors of HIV-related stigmas among African American and Latino religious congregants

    PubMed Central

    Derose, Kathryn Pitkin; Kanouse, David E.; Bogart, Laura M.; Griffin, Beth Ann; Haas, Ann; Stucky, Brian D.; Williams, Malcolm V.; Flórez, Karen R.

    2015-01-01

    Objectives Inform church-based stigma interventions by exploring dimensions of HIV stigma among African American and Latino religious congregants and how these are related to drug addiction and homosexuality stigmas and knowing someone HIV-positive. Methods In-person, self-administered surveys of congregants 18+ years old across two African American and three Latino churches (n=1235, response rate 73%) in a western US city with high HIV prevalence. Measures included 12 items that captured dimensions of HIV stigma, a 5-item scale that assessed attitudes towards people who are addicted to drugs, a 7-item scale assessing attitudes towards homosexuality, and questions regarding socio-demographics and previous communication about HIV. Results 63.8% of survey participants were women, mean age was 40.2 years, and 34.4% were African American, 16.8% were U.S.-born Latinos, 16.0% were foreign-born, English-speaking Latinos, and 32.9% were foreign-born, Spanish-speaking Latinos. Exploratory and confirmatory factor analyses identified four dimensions of HIV stigma – discomfort interacting with people with HIV (4 items, α=0.86), feelings of shame “if you had HIV” (3 items, α=0.78), fears of rejection “if you had HIV” (3 items, α=0.71) and feelings of blame towards people with HIV (2 items, α=0.65). Across all dimensions, after controlling for socio-demographic characteristics and previous communication about HIV, knowing someone with HIV was associated with lower HIV stigma, and greater stigma concerning drug addiction and homosexuality were associated with higher HIV stigma. Conclusions Congregation-based HIV stigma reduction interventions should consider incorporating contact with HIV-affected people. It may also be helpful to address attitudes toward drug addiction and sexual orientation. PMID:26213890

  10. Plate tectonics of the Red Sea and East Africa.

    PubMed

    McKenzie, D P; Davies, D; Molnar, P

    1970-04-18

    The relative motion between the plates on each side of the East African Rift Valley can be obtained from the opening of the Red Sea and the Gulf of Aden. The calculated direction of relative motion agrees well with fault plane solutions for earthquakes north of the equator. PMID:16057189

  11. Plate tectonics of the Red Sea and East Africa.

    PubMed

    McKenzie, D P; Davies, D; Molnar, P

    1970-04-18

    The relative motion between the plates on each side of the East African Rift Valley can be obtained from the opening of the Red Sea and the Gulf of Aden. The calculated direction of relative motion agrees well with fault plane solutions for earthquakes north of the equator.

  12. Obliquely convergent plate motion and its relation with forearc sliver movement, El Salvador volcanic arc

    NASA Astrophysics Data System (ADS)

    Tikoff, B.; DeMets, C.; Garibaldi, N.; Hernandez, W.; Hernandez, D.

    2012-12-01

    The magmatic arc in El Salvador is interpreted to result from the subduction of the Cocos plate underneath the Caribbean plate along the Middle America trench. In addition, El Salvador contains a fore-arc sliver that moves 11 mm/yr westward relative to the back-arc. Well-defined strike-slip faults along the magmatic arc accommodate forearc sliver motion, but are offset at several locations by en echelon pull-apart step-overs with abundant normal faults. All basaltic-andesitic magmatic centers (San Miguel, San Vincente, San Salvador, Santa Ana) are located within these step-overs, while the two major rhyolitic calderas (Ilopango, Coatepeque) occur directly along the strike-slip faults. There are two puzzling aspects about the strike-slip tectonism. First, a silicic, shallow magma body that intrudes the San Miguel fault zone (part of the El Salvador fault system) was emplaced syn-tectonically (sigmoidal field and magnetic foliations, subhorizontally plunging magnetic lineations and dextral shear at the microscale). Within the dextrally sheared portion of the intrusion, an obsidian band with a 40Ar/39Ar age of 7.46 Ma indicates that dextral strike-slip tectonism in the Salvadoran arc has been an ongoing process for ~7.5 Ma. This casts significant doubt on whether Cocos ridge subduction (that started ~1 Ma ago) is the cause of the ongoing forearc movement. The potentially more significant problem is that the fore-arc sliver in El Salvador moves 11 mm/yr westward relative to the back-arc despite a nearly orthogonal angle of convergence (with a convergence rate of ~77 mm/yr) near El Salvador and absence of significant frictional coupling along the subduction interface. Further, GPS indicates that the Nicaraguan and Salvadoran forearcs define a semi-rigid sliver moving at nearly the same trench-parallel rates despite along-trench changes in the subduction angle. Consequently, it is tempting to attribute the movement of both forearc slivers to Cocos ridge subduction

  13. Seasonal variation in the relative dominance of herbivore guilds in an African savanna.

    PubMed

    Davies, Andrew B; van Rensburg, Berndt J; Robertson, Mark P; Levick, Shaun R; Asner, Gregory P; Parr, Catherine L

    2016-06-01

    African savannas are highly seasonal with a diverse array of both mammalian and invertebrate herbivores, yet herbivory studies have focused almost exclusively on mammals. We conducted a 2-yr exclosure experiment in South Africa's Kruger National Park to measure the relative impact of these two groups of herbivores on grass removal at both highly productive patches (termite mounds) and in the less productive savanna matrix. Invertebrate and mammalian herbivory was greater on termite mounds, but the relative importance of each group changed over time. Mammalian offtake was higher than invertebrates in the dry season, but can be eclipsed by invertebrates during the wet season when this group is more active. Our results demonstrate that invertebrates play a substantial role in savanna herbivory and should not be disregarded in attempts to understand the impacts of herbivory on ecosystems.

  14. Seasonal variation in the relative dominance of herbivore guilds in an African savanna.

    PubMed

    Davies, Andrew B; van Rensburg, Berndt J; Robertson, Mark P; Levick, Shaun R; Asner, Gregory P; Parr, Catherine L

    2016-06-01

    African savannas are highly seasonal with a diverse array of both mammalian and invertebrate herbivores, yet herbivory studies have focused almost exclusively on mammals. We conducted a 2-yr exclosure experiment in South Africa's Kruger National Park to measure the relative impact of these two groups of herbivores on grass removal at both highly productive patches (termite mounds) and in the less productive savanna matrix. Invertebrate and mammalian herbivory was greater on termite mounds, but the relative importance of each group changed over time. Mammalian offtake was higher than invertebrates in the dry season, but can be eclipsed by invertebrates during the wet season when this group is more active. Our results demonstrate that invertebrates play a substantial role in savanna herbivory and should not be disregarded in attempts to understand the impacts of herbivory on ecosystems. PMID:27459791

  15. Characterizing kernels of operators related to thin-plate magnetizations via generalizations of Hodge decompositions

    NASA Astrophysics Data System (ADS)

    Baratchart, L.; Hardin, D. P.; Lima, E. A.; Saff, E. B.; Weiss, B. P.

    2013-01-01

    Recently developed scanning magnetic microscopes measure the magnetic field in a plane above a thin-plate magnetization distribution. These instruments have broad applications in geoscience and materials science, but are limited by the requirement that the sample magnetization must be retrieved from measured field data, which is a generically nonunique inverse problem. This problem leads to an analysis of the kernel of the related magnetization operators, which also has relevance to the ‘equivalent source problem’ in the case of measurements taken from just one side of the magnetization. We characterize the kernel of the operator relating planar magnetization distributions to planar magnetic field maps in various function and distribution spaces (e.g., sums of derivatives of Lp (Lebesgue spaces) or bounded mean oscillation (BMO) functions). For this purpose, we present a generalization of the Hodge decomposition in terms of Riesz transforms and utilize it to characterize sources that do not produce a magnetic field either above or below the sample, or that are magnetically silent (i.e. no magnetic field anywhere outside the sample). For example, we show that a thin-plate magnetization is silent (i.e. in the kernel) when its normal component is zero and its tangential component is divergence free. In addition, we show that compactly supported magnetizations (i.e. magnetizations that are zero outside of a bounded set in the source plane) that do not produce magnetic fields either above or below the sample are necessarily silent. In particular, neither a nontrivial planar magnetization with fixed direction (unidimensional) compact support nor a bidimensional planar magnetization (i.e. a sum of two unidimensional magnetizations) that is nontangential can be silent. We prove that any planar magnetization distribution is equivalent to a unidimensional one. We also discuss the advantages of mapping the field on both sides of a magnetization, whenever experimentally

  16. African penguins (Spheniscus demersus) can detect dimethyl sulphide, a prey-related odour.

    PubMed

    Cunningham, Gregory B; Strauss, Venessa; Ryan, Peter G

    2008-10-01

    Although it is well established that certain procellariiform seabirds use odour cues to find prey, it is not clear whether penguins use olfactory cues to forage. It is commonly assumed that penguins lack a sense of smell, yet they are closely related to procellariiforms and forage on similar types of prey in similar areas to many procellariiforms. Such regions are characterized by having high levels of dimethyl sulphide (DMS) a scented compound that many marine animals use to locate foraging grounds. If penguins can smell, DMS may be a biologically relevant scented compound that they may be sensitive to in nature. To test this hypothesis, we investigated whether adult African penguins (Spheniscus demersus) could detect DMS using two separate experiments. We tested wild penguins on Robben Island, South Africa, by deploying mumolar DMS solutions in the colonies, and found that birds slowed down their walking speeds. We also tested captive penguins in a Y-maze. In both cases, our data convincingly demonstrate that African penguins have a functioning sense of smell and are attracted to DMS. The implication of this work is that the detection of changes in the odour landscape (DMS) may assist penguins in identifying productive areas of the ocean for foraging. At-sea studies are needed to investigate this issue further. PMID:18805811

  17. African penguins (Spheniscus demersus) can detect dimethyl sulphide, a prey-related odour.

    PubMed

    Cunningham, Gregory B; Strauss, Venessa; Ryan, Peter G

    2008-10-01

    Although it is well established that certain procellariiform seabirds use odour cues to find prey, it is not clear whether penguins use olfactory cues to forage. It is commonly assumed that penguins lack a sense of smell, yet they are closely related to procellariiforms and forage on similar types of prey in similar areas to many procellariiforms. Such regions are characterized by having high levels of dimethyl sulphide (DMS) a scented compound that many marine animals use to locate foraging grounds. If penguins can smell, DMS may be a biologically relevant scented compound that they may be sensitive to in nature. To test this hypothesis, we investigated whether adult African penguins (Spheniscus demersus) could detect DMS using two separate experiments. We tested wild penguins on Robben Island, South Africa, by deploying mumolar DMS solutions in the colonies, and found that birds slowed down their walking speeds. We also tested captive penguins in a Y-maze. In both cases, our data convincingly demonstrate that African penguins have a functioning sense of smell and are attracted to DMS. The implication of this work is that the detection of changes in the odour landscape (DMS) may assist penguins in identifying productive areas of the ocean for foraging. At-sea studies are needed to investigate this issue further.

  18. Awareness of cancer-related programs and services among rural African Americans.

    PubMed

    Demark-Wahnefried, W; McClelland, J; Campbell, M K; Hoben, K; Lashley, J; Graves, C; Motsinger, B; Rimer, B K

    1998-04-01

    African Americans are at increased risk for cancer and represent an important target population for programs such as Healthy People 2000, the Cancer Information Service (CIS), and the 5 a Day for Better Health Initiative. Yet, awareness of such programs among rural blacks is unknown. This study assessed awareness of these programs and determined related knowledge and beliefs among rural African Americans. It was undertaken as part of the baseline survey for the Black Churches United for Better Health project, a National Cancer Institute-funded initiative. A minority of respondents (n = 3737) demonstrated name recognition of Healthy People 2000 (23.4%), the CIS (42.4%), and the 5 a Day Program (40.7%). Far fewer (7.4%) were able to correctly identify the recommended daily number of servings of fruits and vegetables. Reported family history of cancer was associated with a greater tendency believe that eating more fruits and vegetables can prevent disease. These findings underscore the need for efforts to reach the rural black community with culturally sensitive and stage appropriate cancer prevention messages. Knowledge of family history of cancer may play an important role in targeting subgroups and delivering effective cancer prevention messages.

  19. South African women's conceptualisations of and responses to sexual coercion in relation to hegemonic masculinities.

    PubMed

    Stern, Erin; Buikema, Rosemarie; Cooper, Diane

    2016-01-01

    Despite the documented relationship between hegemonic norms of masculinities and South African men's use of sexual violence, less is known about how women's engagement with norms of masculinity influences their agency in sexually coercive experiences. This study applied a narrative approach to assess how women's understandings of hegemonic male norms affected their perceptions of and responses to sexually coercive experiences. Twenty-five sexual history narrative interviews were conducted with women across five South African provinces representing a range of ages, language and sociocultural backgrounds. Interviews elicited stories of first experiences of sex and the range of sexual relationships through adulthood. Data were analysed using principles of thematic and narrative analysis. Coercive sexual experiences informed many women's normative ideas about men's sexuality including being impulsive, controlling and aggressive. This could underpin women's limited ability to exercise agency and their increased vulnerability to sexual abuse. Some women reported levels of trust and respect in subsequent relationships, which typically involved deconstructing norms of men's use of coercion and moving beyond self-blame and guilt. The findings highlight the need to appreciate the fluid and situated nature of women's agency from a relational perspective in terms of how women condone and challenge gender norms that support men's use of sexual violence in their relationships.

  20. Dyslipidaemia related to insulin resistance and cardiovascular disease in South Asian and West African populations.

    PubMed

    Ewang-Emukowhate, Mfon; Perera, Dilinika; Wierzbicki, Anthony S D M

    2014-01-01

    The global burden of diabetes and cardiovascular disease (CVD) is increasing. Obesity is rapidly increasing worldwide and is associated with dyslipidaemia, metabolic syndrome (MetS) and type 2 diabetes (T2DM). Excess risks of T2DM and CVD are found in migrant Indian Asian and West African populations but with increasing urbanization similar changes are occurring in the original populations and are likely to predispose to a large increase in worldwide burden of CVD. Genetic and environmental factors interacting together play a role in the lipid patterns observed. Dyslipidaemia in the MetS associated with insulin resistance is characterised by an atherogenic lipid profile comprising elevated triglycerides, low high density lipoprotein cholesterol (HDL-C) and increased numbers of small dense low density lipoprotein particles. The pattern of dyslipidaemia varies across different ethnic groups with increases in triglycerides and a reduction in HDL-C being the commonest pattern in non-Caucasians. This review surveys the literature on dyslipidaemia in Indian Asian and West African populations and how it relates to CVD risk in those populations. It is important that dyslipidaemia and other conventional risk factors for CVD are adequately addressed and managed especially in high-risk populations. PMID:24953401

  1. Evolution of African swine fever virus genes related to evasion of host immune response.

    PubMed

    Frączyk, Magdalena; Woźniakowski, Grzegorz; Kowalczyk, Andrzej; Bocian, Łukasz; Kozak, Edyta; Niemczuk, Krzysztof; Pejsak, Zygmunt

    2016-09-25

    African swine fever (ASF) is a notifiable and one of the most complex and devastating infectious disease of pigs, wild boars and other representatives of Suidae family. African swine fever virus (ASFV) developed various molecular mechanisms to evade host immune response including alteration of interferon production by multigene family protein (MGF505-2R), inhibition of NF-κB and nuclear activating factor in T-cells by the A238L protein, or modulation of host defense by CD2v lectin-like protein encoded by EP402R and EP153R genes. The current situation concerning ASF in Poland seems to be stable in comparison to other eastern European countries but up-to-date in total 106 ASF cases in wild boar and 5 outbreaks in pigs were identified. The presented study aimed to reveal and summarize the genetic variability of genes related to inhibition or modulation of infected host response among 67 field ASF isolates collected from wild boar and pigs. The nucleotide sequences derived from the analysed A238L and EP153R regions showed 100% identity. However, minor but remarkable genetic diversity was found within EP402R and MGF505-2R genes suggesting slow molecular evolution of circulating ASFV isolates and the important role of this gene in modulation of interferon I production and hemadsorption phenomenon. The obtained nucleotide sequences of Polish ASFV isolates were closely related to Georgia 2007/1 and Odintsovo 02/14 isolates suggesting their common Caucasian origin. In the case of EP402R and partially in MGF505-2R gene the identified genetic variability was related to spatio-temporal occurrence of particular cases and outbreaks what may facilitate evolution tracing of ASFV isolates. This is the first report indicating identification of genetic variability within the genes related to evasion of host immune system which may be used to trace the direction of ASFV isolates molecular evolution. PMID:27599940

  2. Post-Pan-African tectonic evolution of South Malawi in relation to the Karroo and recent East African rift systems

    NASA Astrophysics Data System (ADS)

    Castaing, C.

    1991-05-01

    Structural studies conducted in the Lengwe and Mwabvi Karroo basins and in the basement in South Malawi, using regional maps and published data extended to cover Southeast Africa, serve to propose a series of geodynamic reconstructions which reveal the persistence of an extensional tectonic regime, the minimum stress σ3 of which has varied through time. The period of Karroo rifting and the tholeiitic and alkaline magmatism which terminated it, were controlled by NW-SE extension, which resulted in the creation of roughly NE-SW troughs articulated by the Tanganyika-Malawi and Zambesi pre-transform systems. These were NW-SE sinistral-slip systems with directions of movement dipping slightly to the Southeast, which enabled the Mwanza fault to play an important role in the evolution of the Karroo basins of the Shire Valley. The Cretaceous was a transition period between the Karroo rifting and the formation of the Recent East African Rift System. Extension was NE-SW, with some evidence for a local compressional episode in the Lengwe basin. Beginning in the Cenozoic, the extension once more became NW-SE and controlled the evolution in transtension of the Recent East African Rift System. This history highlights the major role of transverse faults systems dominated by strike-slip motion in the evolution and perpetuation of the continental rift systems. These faults are of a greater geological persistence than the normal faults bounding the grabens, especially when they are located on major basement anisotropies.

  3. Perceived Factors that Influence Career Decision Self-Efficacy and Engineering Related Goal Intentions of African American High School Students

    ERIC Educational Resources Information Center

    Austin, Chandra Yvette

    2010-01-01

    This study examined the relationship between specific factors believed to influence career decision self-efficacy and math/science related goal intentions (proxy for engineering related goal intentions) among African American high school students. Minority students generally tend to be underrepresented in such careers, as indicated by the National…

  4. "No Matter What I Do They Still Want Their Family": Stressors for African American Grandparents and Other Relatives

    ERIC Educational Resources Information Center

    Linsk, Nathan; Mason, Sally; Fendrich, Michael; Bass, Michael; Prubhughate, Priti; Brown, Allene

    2009-01-01

    Grandparents and other relatives increasingly assume the role of primary caregiver to minor children. This study interviewed family members caring for children whose parents were not available due to parental incarceration, other involvement in the criminal justice system, and substance abuse-related issues. Interviews with 25 African American…

  5. Barriers and Bridges to Positive Cross-Ethnic Relations: African American and White Parent Socialization Beliefs and Practices.

    ERIC Educational Resources Information Center

    Hamm, Jill V.

    2001-01-01

    Using interviews and focus groups, lower and middle socioeconomic status (SES) African American parents and middle SES white parents discussed their objectives regarding cross-ethnic relations and how they helped their children forge positive cross-ethnic relations. The groups relied on different methods to promote socialization. Parents' efforts…

  6. Being selective at the plate: processing dependence between perceptual variables relates to hitting goals and performance.

    PubMed

    Gray, Rob

    2013-08-01

    Performance of a skill that involves acting on a goal object (e.g., a ball to be hit) can influence one's judgment of the size and speed of that object. The present study examined how these action-specific effects are affected when the goal of the actor is varied and they are free to choose between alternative actions. In Experiment 1, expert baseball players were asked to perform three different directional hitting tasks in a batting simulation and make interleaved perceptual judgments about three ball parameters (speed, plate crossing location, and size). Perceived ball size was largest (and perceived speed was slowest) when the ball crossing location was optimal for the particular hitting task the batter was performing (e.g., an "outside" pitch for opposite-field hitting). The magnitude of processing dependency between variables (speed vs. location and size vs. location) was positively correlated with batting performance. In Experiment 2, the action-specific effects observed in Experiment 1 were mimicked by systematically changing the ball diameter in the simulation as a function of plate crossing location. The number of swing initiations was greater when ball size was larger, and batters were more successful in the hitting task for which the larger pitches were optimal (e.g., greater number of pull hits than opposite-field hits when "inside" pitches were larger). These findings suggest attentional accentuation of goal-relevant targets underlies action-related changes in perception and are consistent with an action selection role for these effects. PMID:23163787

  7. Domain repeats related to innate immunity in the South African abalone, Haliotis midae.

    PubMed

    Picone, Barbara; Rhode, Clint; Roodt-Wilding, Rouvay

    2015-10-01

    Molluscs predominately use the cellular defence system as the primary mechanism of defence against pathogenic infection, in which haemocytes play a pivotal role. Haliotis midae is a commercially important South African species that it is susceptible to bacterial pathogens, fungal and yeast infections in the farming environment. The current study aims to enrich the current knowledge regarding H. midae innate immunity by investigating the presence and evolution of domain repeats. The bioinformatics approach used in this study, detected five repeat families in the H. midae transcriptome. These repeats families include mixed alpha and beta (leucine-rich and ankyrin), spectrin repeats, beta-propellers (WD40) and alfa-structure repeat (TPR-like). The expansion of key gene families related to host defence may be important to abalone adaptation to life in a pathogen-rich environment. PMID:25936498

  8. Hormone-related pathways and risk of breast cancer subtypes in African American women.

    PubMed

    Haddad, Stephen A; Lunetta, Kathryn L; Ruiz-Narváez, Edward A; Bensen, Jeannette T; Hong, Chi-Chen; Sucheston-Campbell, Lara E; Yao, Song; Bandera, Elisa V; Rosenberg, Lynn; Haiman, Christopher A; Troester, Melissa A; Ambrosone, Christine B; Palmer, Julie R

    2015-11-01

    We sought to investigate genetic variation in hormone pathways in relation to risk of overall and subtype-specific breast cancer in women of African ancestry (AA). Genotyping and imputation yielded data on 143,934 SNPs in 308 hormone-related genes for 3663 breast cancer cases (1098 ER-, 1983 ER+, 582 ER unknown) and 4687 controls from the African American Breast Cancer Epidemiology and Risk (AMBER) Consortium. AMBER includes data from four large studies of AA women: the Carolina Breast Cancer Study, the Women's Circle of Health Study, the Black Women's Health Study, and the Multiethnic Cohort Study. Pathway- and gene-based analyses were conducted, and single-SNP tests were run for the top genes. There were no strong associations at the pathway level. The most significantly associated genes were GHRH, CALM2, CETP, and AKR1C1 for overall breast cancer (gene-based nominal p ≤ 0.01); NR0B1, IGF2R, CALM2, CYP1B1, and GRB2 for ER+ breast cancer (p ≤ 0.02); and PGR, MAPK3, MAP3K1, and LHCGR for ER- disease (p ≤ 0.02). Single-SNP tests for SNPs with pairwise linkage disequilibrium r (2) < 0.8 in the top genes identified 12 common SNPs (in CALM2, CETP, NR0B1, IGF2R, CYP1B1, PGR, MAPK3, and MAP3K1) associated with overall or subtype-specific breast cancer after gene-level correction for multiple testing. Rs11571215 in PGR (progesterone receptor) was the SNP most strongly associated with ER- disease. We identified eight genes in hormone pathways that contain common variants associated with breast cancer in AA women after gene-level correction for multiple testing. PMID:26458823

  9. Relative time scales reveal multiple origins of parallel disjunct distributions of African caecilian amphibians.

    PubMed

    Loader, Simon P; Pisani, Davide; Cotton, James A; Gower, David J; Day, Julia J; Wilkinson, Mark

    2007-10-22

    Parallel patterns of distribution in different lineages suggest a common cause. Explanations in terms of a single biogeographic event often imply contemporaneous diversifications. Phylogenies with absolute time scales provide the most obvious means of testing temporal components of biogeographic hypotheses but, in their absence, the sequence of diversification events and whether any could have been contemporaneous can be tested with relative date estimates. Tests using relative time scales have been largely overlooked, but because they do not require the calibration upon which absolute time scales depend, they make a large amount of existing molecular data of use to historical biogeography and may also be helpful when calibration is possible but uncertain. We illustrate the use of relative dating by testing the hypothesis that parallel, disjunct east/west distributions in three independent lineages of African caecilians have a common cause. We demonstrate that at least two biogeographic events are implied by molecular data. Relative dating analysis reveals the potential complexity of causes of parallel distributions and cautions against inferring common cause from common spatial patterns without considering the temporal dimension.

  10. Relative time scales reveal multiple origins of parallel disjunct distributions of African caecilian amphibians.

    PubMed

    Loader, Simon P; Pisani, Davide; Cotton, James A; Gower, David J; Day, Julia J; Wilkinson, Mark

    2007-10-22

    Parallel patterns of distribution in different lineages suggest a common cause. Explanations in terms of a single biogeographic event often imply contemporaneous diversifications. Phylogenies with absolute time scales provide the most obvious means of testing temporal components of biogeographic hypotheses but, in their absence, the sequence of diversification events and whether any could have been contemporaneous can be tested with relative date estimates. Tests using relative time scales have been largely overlooked, but because they do not require the calibration upon which absolute time scales depend, they make a large amount of existing molecular data of use to historical biogeography and may also be helpful when calibration is possible but uncertain. We illustrate the use of relative dating by testing the hypothesis that parallel, disjunct east/west distributions in three independent lineages of African caecilians have a common cause. We demonstrate that at least two biogeographic events are implied by molecular data. Relative dating analysis reveals the potential complexity of causes of parallel distributions and cautions against inferring common cause from common spatial patterns without considering the temporal dimension. PMID:17609171

  11. Connective Complexity: African American Adolescents and the Relational Context of Kinship Foster Care

    ERIC Educational Resources Information Center

    Schwartz, Ann

    2008-01-01

    Attempts to address racial disproportionality in child welfare must include a focus on the benefits and challenges facing children in kinship care. African American children not only are overrepresented in the child welfare system, but also are placed disproportionately in kinship foster care. Using a sample of 18 African American adolescents ages…

  12. Recruitment and Retention Strategies Utilized by 1890 Land Grant Institutions in Relation to African American Students

    ERIC Educational Resources Information Center

    Westbrook, Johnnie R.; Alston, Antoine J.

    2007-01-01

    The purpose of this study was to examine the strategies employed by 1890 land grant universities in recruiting and retaining African Americans in agricultural science. Recruitment strategies such as African American agricultural role models, secondary agricultural education, summer enrichment programs, and prior agricultural life experiences were…

  13. Grade-Related Changes in the Production of African American English.

    ERIC Educational Resources Information Center

    Craig, Holly K.; Washington, Julie A.

    2004-01-01

    This investigation examined grade as a source of systematic variation in the African American English (AAE) produced by students in preschool through fifth grades. Participants were 400 typically developing African American boys and girls residing in low- or middle-income homes in an urban-fringe community or midsize central city in the…

  14. African Americans and Boys : Understanding the Literacy Gap, Tracing Academic Trajectories, and Evaluating the Role of Learning-Related Skills

    ERIC Educational Resources Information Center

    Matthews, J. S.; Kizzie, Karmen T.; Rowley, Stephanie J.; Cortina, Kai

    2010-01-01

    In this study, the authors examined the racial and gender gap in the academic development of African American and White children from kindergarten to 5th grade. Their main goal was to determine the extent to which social and behavioral factors, including learning-related skills, problem behaviors, and interpersonal skills, explain these gaps and…

  15. Adaptive and Challenged Parenting among African American Mothers: Parenting Profiles Relate to Head Start Children's Aggression and Hyperactivity

    ERIC Educational Resources Information Center

    Carpenter, Johanna L.; Mendez, Julia

    2013-01-01

    Research Findings: This study used a within-group research design and person-centered analytic methods to identify multidimensional profiles of parenting styles, parenting practices, and related emotional factors in a sample of 274 African American mothers recruited from Head Start programs in the northeastern and southeastern United States.…

  16. Mothers' Academic Gender Stereotypes and Education-Related Beliefs about Sons and Daughters in African American Families

    ERIC Educational Resources Information Center

    Wood, Dana; Kurtz-Costes, Beth; Rowley, Stephanie J.; Okeke-Adeyanju, Ndidi

    2010-01-01

    The role of African American mothers' academic gender stereotype endorsement in shaping achievement-related expectations for and perceptions of their own children was examined. Mothers (N = 334) of 7th and 8th graders completed measures of expectations for their children's future educational attainment, perceptions of their children's academic…

  17. The Psychosocial Adjustment of African American Youth from Single Mother Homes: The Relative Contribution of Parents and Peers

    ERIC Educational Resources Information Center

    Chester, Charlene; Jones, Deborah J.; Zalot, Alecia; Sterrett, Emma

    2007-01-01

    This study examined the relative roles of parents and peers in the psychosocial adjustment of African American youth (7-15 years old) from single mother homes (N = 242). Main effects of both positive parenting and peer relationship quality were found for youth depressive symptoms. In addition, a main effect of peer relationship quality and an…

  18. Relations between Perceived Competence, Importance Ratings, and Self-Worth among African American School-Age Children

    ERIC Educational Resources Information Center

    Grier, Leslie K.

    2013-01-01

    The purpose of this research was to investigate how domain-specific importance ratings affect relations between perceived competence and self-worth among African American school-age children. Importance ratings have been found to affect the strength of the relationship between perceived competence and self-worth and have implications for…

  19. Bulbous epiphysis and popcorn calcification as related to growth plate differentiation in osteogenesis imperfecta

    PubMed Central

    Brizola, Evelise; McCarthy, Edward; Shapiro, Jay Robert

    2015-01-01

    Summary Background Osteogenesis Imperfecta (OI) is an heritable systemic disorder of connective tissue due to different sequence variants in genes affecting both the synthesis of type I collagen and osteoblast function. Dominant and recessive inheritance is recognized. Approximately 90% of the OI cases are due to mutations in COL1A1/A2 genes. We clinically and radiologically describes an adult male with type III osteogenesis imperfecta who presents a rare bone dysplasia termed bulbous epiphyseal deformity in association with popcorn calcifications. Popcorn calcifications may occur with bulbous epiphyseal deformity or independently. Methods Molecular analysis was performed for COL1A1, COL1A2, LEPRE1 and WNT1 genes. Results An uncommon COL1A1 mutation was identified. Clinical and radiological exams confirmed a distinctive bulbous epiphyseal deformity with popcorn calcifications in distal femurs. We have identified four additional OI patients reported in current literature, whose X-rays show bulbous epiphyseal deformity related to mutations in CR-TAP, LEPRE1 and WNT1 genes. Conclusion The mutation identified here had been previously described twice in OI patients and no previous correlation with bulbous epiphyseal deformity was described. The occurrence of this bone dysplasia focuses attention on alterations in normal growth plate differentiation and the subsequent effect on endochondral bone formation in OI. PMID:26604951

  20. HIV-related stigma in a sample of HIV-affected older female African American caregivers

    PubMed

    Poindexter; Linsk

    1999-01-01

    Older women of color increasingly act as informal caregivers for adults and children with HIV disease. Nineteen older female (mostly African American) informal caregivers of HIV-infected individuals participated in qualitative interviews to explore their experiences with HIV-related stigma. Perceived and directly experienced stigma were examined in the context of disclosure of the presence of HIV disease. Overt HIV-related stigma was rarely experienced by these respondents, primarily because they had not widely disclosed the presence of HIV in the family and therefore had not given anyone the opportunity to ostracize or judge them. HIV-related stigma was internalized, so that disclosure decisions were based on their anticipation of censure. There also was evidence of associative stigma and of stigma management. The findings suggest the need for social work practitioners to increase awareness of the needs of stigmatized, isolated HIV-affected caregivers. Practitioners should conduct aggressive outreach and strive to provide more support to this often invisible population of caregivers to HIV-infected people. PMID:9922729

  1. Application of orthogonality-relation for the separation of Lamb modes at a plate edge: numerical and experimental predictions.

    PubMed

    Ratassepp, M; Klauson, A; Chati, F; Léon, F; Décultot, D; Maze, G; Fritzsche, M

    2015-03-01

    In this study the orthogonality relation-based method for post-processing finite element (FE) predictions and experimental measurements is applied in order to separate Lamb modes at a plate edge at normal incidence. The scattered wave field from the free edge is assumed to be a superposition of all the eigenmodes of an infinite plate. The eigenmode amplitudes of the reflected wave field are determined by implementing the orthogonality-based method on the measured plate edge displacements. Overlapping wavepackets of Lamb modes at a plate edge are simulated by using the FE model and the experiment in the case of an incident S0 mode in a plate with a notch. In the experiment a 3D Scanning Laser Doppler Vibrometer (3D SLDV) (Johansmann and Sauer, 2005) is used to measure 3 dimensional vibrations and thus the edge two-dimensional displacement components simultaneously. It is demonstrated that it is possible to extract signals of various propagating and non-propagating modes in time-domain. The influences of the errors in practical measurements on the extraction procedure have also been studied.

  2. African American college students' health behaviors and perceptions of related health issues.

    PubMed

    Ford, D S; Goode, C R

    1994-03-01

    The authors identify specific health-related behaviors of African American college students and compare them with the students' perceptions of corresponding health issues. Among students surveyed, the rate of cigarette smoking (4%) was very low compared with smoking rates found in a national survey (14%); but alcohol consumption was relatively high (63%), although lower than the national average of 91%. More men than women smoked, but more women than men reported they drank alcoholic beverages. Most students (90.2%) said they did not usually eat breakfast, 73.6% reported that their diets were not nutritionally balanced, and the majority (55.4%) were not involved in daily physical activity. More than half (63%) of the students reported satisfactorily handling stress, and 74.1% indicated that they were sexually active. Respondents perceived the most important health issues facing college students as HIV/AIDS and sexually transmitted diseases (STDs), birth control, date rape, stress management, suicide, and alcohol and other drugs. PMID:8201133

  3. Intergroup Contact is Related to Evaluations of Interracial Peer Exclusion in African American Students.

    PubMed

    Ruck, Martin D; Park, Henry; Crystal, David S; Killen, Melanie

    2015-06-01

    There are few published studies on the influence of intergroup contact on ethnic minority public school students' evaluations of interracial exclusion. In this study, African American children and adolescents (N = 158, 4th, 7th, and 10th grade; 67.1%) were individually interviewed regarding peer exclusion for scenarios depicting cross-race peer exclusion in various contexts. The level of positive intergroup contact, attribution of motives for exclusion, wrongfulness ratings, reasoning about exclusion, estimations of the frequency of exclusion, and awareness of the use of stereotypes to justify racial exclusion were assessed. Intergroup contact was significantly related to attributions of racial motives, higher ratings of wrongfulness, greater use of moral reasoning, and higher estimations of the frequency of exclusion. In addition to context effects, with increasing grade participants were more likely to refer to the historical and social circumstances contributing to the manifestation of racial stereotypes used to justify exclusion. The findings are discussed in terms of the existing research on intergroup relations and evaluations of social exclusion.

  4. South African experience with asbestos related environmental mesothelioma: is asbestos fiber type important?

    PubMed

    White, Neil; Nelson, Gill; Murray, Jill

    2008-10-01

    South Africa (SA), a country in which all three commercially important asbestos minerals have been mined and milled, has retained proven cases of mesothelioma linked with environmental exposure to asbestos. This study illustrates the importance of fiber type in the occurrence of environmental mesothelioma. Four studies have reviewed the source of occupational or environmental asbestos exposure in 504 histologically proven cases of mesothelioma in South Africa. One hundred and eighteen cases (23%) were thought to be related to environmental exposure to asbestos. In the vast majority of these cases, exposure was linked to crocidolite mining activities in the Northern Cape Province. Two cases were thought to have occurred in relation to amosite and Transvaal crocidolite exposure in the Limpopo Province. In the balance of cases there was some uncertainty. No cases were reported with exposure to South African chrysotile. Consequently, in the vast majority of cases of mesothelioma, environmental exposure to asbestos occurred in the Northern Cape Province, in proximity to mines, mills and dumps where crocidolite was processed. Crocidolite appears to be far more mesotheliomagenic than amosite, and chrysotile has not been implicated in the disease. This is true for both occupationally and environmentally exposed individuals.

  5. New Evidence that the Emperor Seamount Chain Records Motion of the Pacific Plate Relative to the Deep Mantle

    NASA Astrophysics Data System (ADS)

    Gordon, Richard; Seidman, Lily

    2016-04-01

    A key question for Pacific and circum-Pacific tectonics with implications for mantle convection is whether the Emperor seamount chain records the northward motion of the Pacific plate relative to the deep mantle. To investigate this question, we determine a new Pacific plate paleomagnetic pole for ≈60 Ma BP from the analysis of the skewness of marine magnetic anomaly 26r recording Pacific-Farallon motion in low paleolatitudes. We further update a previously published Pacific plate pole for ≈65 Ma from the analysis of anomalies 27r to 31 by incorporating a larger correction for anomalous skewness. These two poles, along with prior poles for 58 Ma and 72 Ma allow us to test how much, if any, the Hawaiian hotspot moved relative to the spin axis for ≈14 Ma of the ≈30 Ma during which the Emperor chain was formed. We find that the Hawaiian hotspot moved insignificantly southward (4 ±17 mm/a (95% confidence limits)) from 72 Ma to 58 Ma while the Pacific plate moved significantly northward (42 ± 17 mm/a (95% confidence limits)). We further compare the apparent polar wander of the Pacific hotspots with that of the Indo-Atlantic hotspots over the past 65 Ma. The two paths indicate a jump of ≈8° in the position of the spin axis relative to global hotspots between ≈60 Ma and ≈45 Ma presumably due to true polar wander.

  6. Coping Strategies as Moderators of the Relation between Individual Race-Related Stress and Mental Health Symptoms for African American Women

    ERIC Educational Resources Information Center

    Greer, Tawanda M.

    2011-01-01

    The purpose of this investigation was to examine coping strategies as moderators of the relationship between individual race-related stress and mental health symptoms among a sample of 128 African American women. Coping strategies refer to efforts used to resolve problems and those used to manage, endure, or alleviate distress. Culture-specific…

  7. Developmental and ethnic issues experienced by emerging adult African American women related to developing a mature love relationship.

    PubMed

    Tyson, Sheryl Y

    2012-01-01

    This qualitative study explored perspectives of emerging adult African American women on the development of mature love relationships. Inductive analysis of focus group interviews, conducted with a purposive sample of 31 African American women, yielded themes related to relationship goals and characteristics, and interpersonal and societal challenges to finding the right partner and developing a mature love relationship. Core categories that emerged from analysis of the discussions were (1) age and relationship goal differences within the emerging adult group, (2) mature love relationship goals and characteristics, (3) interpersonal obstacles to finding the right partner, and (4) societal obstacles to finding the right partner. Two approaches-black womanist/feminist thought (Collins, 2000 ; Walker, 1983 ) and relationship maturity theory (Paul & White, 1990 )-were then combined to explain the influence of historic and contemporary interpersonal and societal factors on developmental and ethnic issues that challenge positive gender identity formation, hasten intimacy maturity, and hinder the development of mature love relationships among emerging adult African American women. For these women, premature responsibility, especially early caregiver burden, was related to the early development of intimacy capacity and the desire for a mature love relationship, to be protected, and to have someone to help carry the load. Interracial dating, negative stereotypic images of African American women, and even positive images of enduring black love relationships posed difficult challenges to positive identity formation and intimacy maturity. A primary challenge was to counteract negative stereotypic images, so that they could develop their own self-identities as women and as relationship partners.

  8. AN INTERVENTION TO REDUCE HIV-RELATED STIGMA IN PARTNERSHIP WITH AFRICAN AMERICAN AND LATINO CHURCHES

    PubMed Central

    Derose, Kathryn Pitkin; Bogart, Laura M.; Kanouse, David E.; Felton, Alexandria; Collins, Deborah Owens; Mata, Michael A.; Oden, Clyde W.; Domínguez, Blanca X.; Flórez, Karen R.; Hawes-Dawson, Jennifer; Williams, Malcolm V.

    2014-01-01

    HIV-related stigma negatively affects prevention and care, and community-based interventions are needed. Here we describe the development of a multi-ethnic, faith-based intervention to reduce HIV stigma that included: educational workshops on HIV, testing, and stigma; peer leader workshops using role plays and drawing on principles of motivational interviewing; a pastor-delivered sermon on HIV that incorporated theological reflection and an imagined contact scenario; and congregation-based HIV testing events. Lessons learned include: partnership development is essential and requires substantial investment; tailoring intervention components to single race-ethnic groups may not be preferable in diverse community settings; and adapting testing processes to be able to serve larger numbers of people in shorter time frames is needed for congregational settings. This development process successfully combined the rigorous application of social science theory and community engagement to yield a multifaceted HIV stigma reduction intervention appropriate for Protestant and Catholic churches in African American and Latino communities. PMID:24450276

  9. What Works? A Qualitative Examination of the Factors Related to the Academic Success of African American Males at a Predominantly White College in the South

    ERIC Educational Resources Information Center

    Robertson, Ray V.; Mason, Danielle

    2008-01-01

    Our study examined the factors related to the retention/academic success of African American males at a mid-sized, regional, predominantly white university in the south. The selected university has an African American male graduation rate, of approximately twenty three percent, which is thirteen percentage points below the national Black male…

  10. Health Emergency 2003: The Spread of Drug-Related AIDS and Hepatitis C among African American and Latinos. Health Emergency Series.

    ERIC Educational Resources Information Center

    Day, Dawn

    This report is the fifth in a series detailing the impact of the injection-related AIDS epidemic on African Americans and Latinos. Ten chapters include: (1) "Health Emergency: The Spread of AIDS among African Americans Who Inject Drugs"; (2) "Health Emergency: The Spread of AIDS Among Latinos Who Inject Drugs"; (3) "A Neglected Opportunity: Drug…

  11. Simultaneous modeling of habitat suitability, occupancy, and relative abundance: African elephants in Zimbabwe

    USGS Publications Warehouse

    Martin, Julien; Chamaille-Jammes, Simon; Nichols, James D.; Fritz, Herve; Hines, James E.; Fonnesbeck, Christopher J.; MacKenzie, Darryl I.; Bailey, Larissa L.

    2010-01-01

    The recent development of statistical models such as dynamic site occupancy models provides the opportunity to address fairly complex management and conservation problems with relatively simple models. However, surprisingly few empirical studies have simultaneously modeled habitat suitability and occupancy status of organisms over large landscapes for management purposes. Joint modeling of these components is particularly important in the context of management of wild populations, as it provides a more coherent framework to investigate the population dynamics of organisms in space and time for the application of management decision tools. We applied such an approach to the study of water hole use by African elephants in Hwange National Park, Zimbabwe. Here we show how such methodology may be implemented and derive estimates of annual transition probabilities among three dry-season states for water holes: (1) unsuitable state (dry water holes with no elephants); (2) suitable state (water hole with water) with low abundance of elephants; and (3) suitable state with high abundance of elephants. We found that annual rainfall and the number of neighboring water holes influenced the transition probabilities among these three states. Because of an increase in elephant densities in the park during the study period, we also found that transition probabilities from low abundance to high abundance states increased over time. The application of the joint habitat–occupancy models provides a coherent framework to examine how habitat suitability and factors that affect habitat suitability influence the distribution and abundance of organisms. We discuss how these simple models can further be used to apply structured decision-making tools in order to derive decisions that are optimal relative to specified management objectives. The modeling framework presented in this paper should be applicable to a wide range of existing data sets and should help to address important ecological

  12. Masculinity and Race-Related Factors as Barriers to Health Help-Seeking Among African American Men.

    PubMed

    Powell, Wizdom; Adams, Leslie B; Cole-Lewis, Yasmin; Agyemang, Amma; Upton, Rachel D

    2016-01-01

    Men's tendency to delay health help-seeking is largely attributed to masculinity, but findings scarcely focus on African American men who face additional race-related, help-seeking barriers. Building principally on reactance theory, we test a hypothesized model situating racial discrimination, masculinity norms salience (MNS), everyday racism (ERD), racial identity, sense of control (SOC), and depressive symptomatology as key barriers to African American men's health help-seeking. A total of 458 African American men were recruited primarily from US barbershops in the Western and Southern regions. The primary outcome was Barriers to Help-Seeking Scale (BHSS) scores. The hypothesized model was investigated with confirmatory factor and path analysis with tests for measurement invariance. Our model fit was excellent [Formula: see text] CFI = 0.99; TLI = 1.00; RMSEA = 0.00, and 90% CI [0.00, 0.07] and operated equivalently across different age, income, and education strata. Frequent ERD and higher MNS contributed to higher BHHS scores. The relationship between ERD exposure and BHHS scores was partially mediated by diminished SOC and greater depressive symptomatology. Interventions aimed at addressing African American men's health help-seeking should not only address masculinity norms but also threats to sense of control, and negative psychological sequelae induced by everyday racism.

  13. Masculinity and Race-Related Factors as Barriers to Health Help-Seeking Among African American Men.

    PubMed

    Powell, Wizdom; Adams, Leslie B; Cole-Lewis, Yasmin; Agyemang, Amma; Upton, Rachel D

    2016-01-01

    Men's tendency to delay health help-seeking is largely attributed to masculinity, but findings scarcely focus on African American men who face additional race-related, help-seeking barriers. Building principally on reactance theory, we test a hypothesized model situating racial discrimination, masculinity norms salience (MNS), everyday racism (ERD), racial identity, sense of control (SOC), and depressive symptomatology as key barriers to African American men's health help-seeking. A total of 458 African American men were recruited primarily from US barbershops in the Western and Southern regions. The primary outcome was Barriers to Help-Seeking Scale (BHSS) scores. The hypothesized model was investigated with confirmatory factor and path analysis with tests for measurement invariance. Our model fit was excellent [Formula: see text] CFI = 0.99; TLI = 1.00; RMSEA = 0.00, and 90% CI [0.00, 0.07] and operated equivalently across different age, income, and education strata. Frequent ERD and higher MNS contributed to higher BHHS scores. The relationship between ERD exposure and BHHS scores was partially mediated by diminished SOC and greater depressive symptomatology. Interventions aimed at addressing African American men's health help-seeking should not only address masculinity norms but also threats to sense of control, and negative psychological sequelae induced by everyday racism. PMID:27337619

  14. Kinematics of the New Zealand plate boundary: Relative motion by GPS across networks of 1000 km and 50 km spacing

    NASA Technical Reports Server (NTRS)

    Meertens, Charles M.; Rocken, Christian; Perin, Barbara; Walcott, Richard

    1993-01-01

    The NASA/DOSE 'Kinematics of the New Zealand Plate Boundary' experiment is a four-year cooperative Global Positioning System (GPS) experiment involving 6 universities and institutions in New Zealand and the United States. The investigation covers two scales, the first on the scale of plates (approximately 1000 km) and the second is on the scale of the plate boundary zone (approximately 50 km). In the first portion of the experiment, phase A, the objective is to make direct measurements of tectonic plate motion between the Australian and Pacific plates using GPS in order to determine the Euler vector of this plate pair. The phase A portion of this experiment was initiated in December 1992 with the first-epoch baseline measurements on the large scale network. The network will be resurveyed two years later to obtain velocities. The stations which were observed for phase A are shown and listed. Additional regional stations which will be used for this study are listed and are part of either CIGNET or other global tracking networks. The phase A portion of the experiment is primarily the responsibility of the UNAVCO investigators. Therefore, this report concentrates on phase A. The first year of NASA funding for phase A included only support for the field work. Processing and analysis will take place with the second year of funding. The second part of the experiemnt measured relative motion between the Australian and Pacific plates across the pate boundary zone between Hokitika and Christchurch on the South Island of New Zealand. The extent and rate of deformation will be determined by comparisons with historical, conventional surveys and by repeated GPS measurements to be made in two years. This activity was the emphasis of the LDGO portion of the study. An ancillary experiment, phase C, concentrated on plate boundary deformation in the vicinity of Wellington and was done as part of training during the early portion of the field campaign. Details of the objectives of the

  15. The effects of plate-bending-related aquifer thickening on temperatures in the Japan Trench subduction zone

    NASA Astrophysics Data System (ADS)

    Spinelli, G. A.

    2015-12-01

    Accurate subduction zone thermal models are necessary to understand a wide range of geophysical and geochemical processes, including: metamorphic reaction progress, mantle wedge hydration, and melt generation. For decades, plate convergence rate and subducting plate age and dip have been recognized as basic factors affecting subduction zone temperatures. Recent discoveries highlight the important effects of fluid circulation in oceanic lithosphere on subduction zone temperatures. However, there are contrasting hypotheses for the distribution of the regions within the oceanic lithosphere that host vigorous fluid circulation: one with a constant thickness aquifer extending both seaward and landward of the trench, one with an aquifer that thickens as it approaches the trench (due to bend-related faulting) but assumes vigorous fluid circulation only occurs prior to subduction, and a hybrid that considers both aquifer thickening seaward of the trench and continued circulation in the subducting plate. I examine the effects of bend-related aquifer thickening on temperatures within the Japan Trench subduction zone with a suite of thermal models. Kawada et al. [2014] hypothesize that plate-bending faults offshore northern Japan increase the thickness of the oceanic crustal aquifer, and therefore influence heat redistribution in the system. Existing models explore the effects of aquifer thickening on heat flux seaward of the trench, but they do not examine the effects of this process on temperatures within the subduction zone; additionally, they treat the aquifer seaward of the trench as completely isolated from the aquifer in the subducted plate. Here, I exploit the fact that aquifer thickening from the outer rise to the trench and continued fluid circulation in subducting crust are expected to produce distinct surface heat flux anomalies, in order to constrain the thermal effects of each process. I find the combinations of the amount of aquifer thickening and the degree of

  16. Relative potentials of concentrating and two-axis tracking flat-plate photovoltaic arrays for central-station applications

    NASA Technical Reports Server (NTRS)

    Borden, C. S.; Schwartz, D. L.

    1984-01-01

    The purpose of this study is to assess the relative economic potentials of concenrating and two-axis tracking flat-plate photovoltaic arrays for central-station applications in the mid-1990's. Specific objectives of this study are to provide information on concentrator photovoltaic collector probabilistic price and efficiency levels to illustrate critical areas of R&D for concentrator cells and collectors, and to compare concentrator and flat-plate PV price and efficiency alternatives for several locations, based on their implied costs of energy. To deal with the uncertainties surrounding research and development activities in general, a probabilistic assessment of commercially achievable concentrator photovoltaic collector efficiencies and prices (at the factory loading dock) is performed. The results of this projection of concentrator photovoltaic technology are then compared with a previous flat-plate module price analysis (performed early in 1983). To focus this analysis on specific collector alternatives and their implied energy costs for different locations, similar two-axis tracking designs are assumed for both concentrator and flat-plate options.

  17. Mantle plume related dynamic uplift and plate kinematics: The NE Atlantic case with global implications.

    NASA Astrophysics Data System (ADS)

    Skogseid, Jakob; Khabbaz Ghazian, Reza; Lunt, Ian

    2014-05-01

    At present a pronounced residual depth anomaly (RDA), centred on Iceland, is characterizing the bathymetry of the NE Atlantic region. For the oceanic lithosphere this anomaly represents a <500 to >2500 m elevation difference compared to 'normal' oceanic lithosphere. The observed depth anomaly has since Cochran and Talwani (1978) been ascribed to a 200 -300 km thick moderate thermal anomaly beneath the oceanic lithosphere, the existence of which today has been proven by a sizable low velocity zone on seismic tomography data. The sub-lithosphere low velocities are, however, not limited to the oceanic domain, but also underlie the adjacent continental lithosphere, thus causing a similar magnitude anomalous elevation of the continental shelves and landmasses. The thermal anomaly is presumed to relate to the arrival of the Iceland mantle plume demonstrated by excess Paleocene and Early Eocene magmatism and the formation of the North Atlantic Volcanic Province (NAVP), and subsequent volcanic margin formation. The present width of the RDA compares with the size of the regions that experienced excess magmatism during rifting and breakup, which implies that the sub-lithospheric thermally anomalous body was emplaced in Paleocene time, but still resides in the area. This presentation aims to describe the temporal and spatial development of uplift based on combining plate kinematic modeling with models of lithospheric and plume body thickness development through Late Cretaceous-Paleocene extension, and subsequent seafloor spreading. The model prediction of uplift compares well with descriptions of erosional episodes and depositional sequences off Greenland, in the Northern North Sea, off mid-Norway and in the SW Barents Sea, and represents a mechanism that explains the present elevation of East Greenland as well as western Norway. In a global perspective the close correlation between Large Igneous Provinces (LIP's), the arrival of known mantle plumes and formation of volcanic

  18. Trichotillomania symptoms in African American women: are they related to anxiety and culture?

    PubMed

    Neal-Barnett, Angela; Statom, Deborah; Stadulis, Robert

    2011-08-01

    Trichotillomania (TTM) is a little understood disorder that has been underresearched in the African American community. Furthermore, the incorporation of cultural factors into TTM research has virtually been ignored. Existing data from an African American college student population suggest TTM is associated with high levels of anxiety. In this study, we explored anxiety symptoms and cultural hair messages in an African American female community sample with TTM symptoms. We predicted high levels of TTM severity and impairment would be associated with high level of anxiety symptoms. We also predicted that cultural messages about hair will influence both TTM and anxiety symptoms. In this telephone study, 41 African American females participated in interviews about their TTM. TTM impairment and severity was positively correlated with general anxiety symptoms as measured on the Symptom Checklist 90-Revised (SCL 90-R(®) ). Severity was also positively correlated with obsessive-compulsive symptoms. Given the significance of hair for African American women, we also explored the childhood cultural messages receive about hair. Over half the sample received at least one cultural message about hair. Although many women received the same message, the value they placed on the message differed. Messages received about hair were not associated with TTM severity or impairment. The association among obsessive-compulsive symptoms and hair messages approached significance. Results highlight the importance of assessing anxiety comorbidity and culture with African American TTM samples. Little is known about TTM in African American samples. Existing research indicates this population seeks TTM help from their hairdressers. Among college students, a significant correlation has been found for anxiety as measured on the Beck Anxiety Inventory and TTM. To the best of our knowledge, this is the first paper to examine cultural messages about hair in an African American sample. In addition

  19. Differential Persistence of Foot-and-Mouth Disease Virus in African Buffalo Is Related to Virus Virulence

    PubMed Central

    Maree, Francois; de Klerk-Lorist, Lin-Mari; Gubbins, Simon; Zhang, Fuquan; Seago, Julian; Pérez-Martín, Eva; Reid, Liz; Scott, Katherine; van Schalkwyk, Louis; Bengis, Roy; Juleff, Nicholas

    2016-01-01

    ABSTRACT Foot-and-mouth disease (FMD) virus (FMDV) circulates as multiple serotypes and strains in many regions of endemicity. In particular, the three Southern African Territories (SAT) serotypes are maintained effectively in their wildlife reservoir, the African buffalo, and individuals may harbor multiple SAT serotypes for extended periods in the pharyngeal region. However, the exact site and mechanism for persistence remain unclear. FMD in buffaloes offers a unique opportunity to study FMDV persistence, as transmission from carrier ruminants has convincingly been demonstrated for only this species. Following coinfection of naive African buffaloes with isolates of three SAT serotypes from field buffaloes, palatine tonsil swabs were the sample of choice for recovering infectious FMDV up to 400 days postinfection (dpi). Postmortem examination identified infectious virus for up to 185 dpi and viral genomes for up to 400 dpi in lymphoid tissues of the head and neck, focused mainly in germinal centers. Interestingly, viral persistence in vivo was not homogenous, and the SAT-1 isolate persisted longer than the SAT-2 and SAT-3 isolates. Coinfection and passage of these SAT isolates in goat and buffalo cell lines demonstrated a direct correlation between persistence and cell-killing capacity. These data suggest that FMDV persistence occurs in the germinal centers of lymphoid tissue but that the duration of persistence is related to virus replication and cell-killing capacity. IMPORTANCE Foot-and-mouth disease virus (FMDV) causes a highly contagious acute vesicular disease in domestic livestock and wildlife species. African buffaloes (Syncerus caffer) are the primary carrier hosts of FMDV in African savannah ecosystems, where the disease is endemic. We have shown that the virus persists for up to 400 days in buffaloes and that there is competition between viruses during mixed infections. There was similar competition in cell culture: viruses that killed cells quickly

  20. Meso-cenozoic volcanic rocks in east China and adjacent areas with relation to plate tectonics

    NASA Astrophysics Data System (ADS)

    Zheng, Xuezheng

    1985-03-01

    Meso-Cenozoic calc-alkaline volcanic rocks and granites in the East China region are composed of four NE belts from west to east; the Trassic belt in the middle and east Mongolia, the Jurassic-Creta-ceous belt in East China, the Paleogene belt in the East China Sea and the Neogene-Quaternary belt in southwestern Japan-Okinawa and northeastern Japan-Izu-Bonin-Mariana volcanic arcs. They are nearly parallel to the Benioff zones of the ancient Pacific Plate on one hand and become older as the distance from the Pacific Ocean increases on the other hand. This sequence is in reverse order to that in South and North America. There are two age-peaks among them: one is in the early Cretaceous and the other in the Miocene, in good agreement with the time when the sea-floor spreading of the ancient Pacific Plate became fast during 115-85 Ma and after 25 Ma (Hilde et al., 1977). The second belt in East China consists of three paralleled NE sub-belts and two E-W sub-belts on which the volcanoes erupted throughout the Jurassic-Cretaceous period but the strong eruption centres were moving eastward with time. The continental rift-type basalts occurred in the middle of East China in Paleogene time. The Neogene-Quaternary basalts in East China belong to crack-type (Zheng and Zao, 1984). These ages and types of rocks suggest that subduction of the ancient Pacific Plate began at Triassic time and became stronger later. The Meso-Cenozoic volcanic belts, from north to south, can be divided into three different regions by the Tianshan-Xinganling and the Qinling tectonic lines in the middle of East Asia and two regions in the middle of the western Pacific. This difference has been getting clear since the Triassic time. On the whole, the Meso-Cenozoic volcanism in the middle of the western Pacific records reaction between the Asian Plate and the ancient Pacific Plate or the Indian Plate.

  1. Space use of African wild dogs in relation to other large carnivores.

    PubMed

    Darnell, Angela M; Graf, Jan A; Somers, Michael J; Slotow, Rob; Szykman Gunther, Micaela

    2014-01-01

    Interaction among species through competition is a principle process structuring ecological communities, affecting behavior, distribution, and ultimately the population dynamics of species. High competition among large African carnivores, associated with extensive diet overlap, manifests in interactions between subordinate African wild dogs (Lycaon pictus) and dominant lions (Panthera leo) and spotted hyenas (Crocuta crocuta). Using locations of large carnivores in Hluhluwe-iMfolozi Park, South Africa, we found different responses from wild dogs to their two main competitors. Wild dogs avoided lions, particularly during denning, through a combination of spatial and temporal avoidance. However, wild dogs did not exhibit spatial or temporal avoidance of spotted hyenas, likely because wild dog pack sizes were large enough to adequately defend their kills. Understanding that larger carnivores affect the movements and space use of other carnivores is important for managing current small and fragmented carnivore populations, especially as reintroductions and translocations are essential tools used for the survival of endangered species, as with African wild dogs.

  2. Improving Health-Related Quality of Life in Older African-Americans and non-Latino Whites

    PubMed Central

    Jimenez, Daniel E.; Begley, Amy; Bartels, Stephen J.; Alegría, Margarita; Thomas, Stephen B.; Quinn, Sandra C.; Reynolds, Charles F.

    2014-01-01

    Objective To compare the effect of problem solving therapy against a health-promotion intervention (dietary practices) on health-related quality of life (HRQOL) and examine if there is a differential effect on non-Latino Whites and African-Americans between the two interventions. This paper also explores participant characteristics (problem solving style and physical functioning) as potential predictors of HRQOL. Methods Secondary analysis of data from a randomized depression prevention trial involving 247 older adults (154 non-Latino Whites, 90 African-Americans, 3 Asians). Participants were randomly assigned to receive either problem solving therapy for primary care (PST-PC) or coaching in healthy dietary practices (DIET). Results Both PST-PC and DIET improved HRQOL over two years and did not differ significantly from each other. African-Americans in both conditions had greater improvements in mental health-related quality of life (MHRQOL) compared to non-Latino Whites. In addition, higher social problem solving and physical functioning were predictive of improved MHRQOL. Conclusions PST-PC and DIET have the potential to improve health-related quality of life in a culturally relevant manner. Both hold promise as effective and potentially scalable interventions that could be generalized to highly disadvantaged populations in which little attention to HRQOL has been paid. PMID:25171889

  3. Relative movements between Kinemax Plus tibial inserts and the tibial base-plates.

    PubMed

    Ash, H E; Scholes, S C; Parkin, R; Unsworth, A

    2003-01-01

    Tests were performed on six large Kinemax Plus knee bearings (snap-fit design) to evaluate the amount of movement between 10- and 15-mm-thick tibial inserts and the tibial base plates. The knee bearings were tested up to 1 x 10(6) cycles on the Durham six-station knee wear simulator which subjected the bearings to similar motion and loading profiles that would be experienced by the natural knee during walking. Although passive internal/external (I/E) rotation was allowed, no active I/E rotation was applied. The movement of the tibial inserts was measured with dial gauges (accuracy +/-0.01 mm) before and after the bearings were tested on the simulator, when unloaded, and throughout the tests while the bearings were being dynamically loaded in the simulator. Movement occurred between the tibial insert and the tibial base plate after initial assembly due to the snap-fit mechanism used to locate the tibial insert within the tibial base plate. However this decreased appreciably when the bearings were loaded in the simulator. The amount of movement did not change with time when the bearings were continuously loaded in the simulator. However, after each test the amount of movement of the tibial inserts, when unloaded, was only 65 per cent (anterior-posterior) and 46 per cent (medial-lateral) of the values before the test. This was thought to be due to creep of the ultra-high molecular weight polyethylene (UHMWPE) inserts. The movement between the tibial insert and tibial base plate in situ is likely to be much less than that observed by a surgeon at the time of assembly due to loading of the knee bearing in the body. However, the amount of movement when the tibial inserts are loaded may still be great enough to produce a second interface where wear of the tibial insert may take place. PMID:12666776

  4. Forced relative displacements of the core and mantle as the basic mechanism of secular changes of the Earth shape and lithosphere plates tectonics

    NASA Astrophysics Data System (ADS)

    Barkin, Yury

    2010-05-01

    The summary. In the work planetary changes of a figure of the Earth and geoid in present epoch are discussed. Contrast and asymmetric geodetic changes of northern and southern hemispheres are revealed. The phenomenon of lengthening of latitude circles of a southern hemisphere and shortening of lengths of latitude circles of northern hemisphere, the phenomenon of expansion of a southern hemisphere and, accordingly, compression of northern hemisphere in relation to the center of mass of the Earth have been predicted. The reasons of the planetary tendency of displacement (drift) of plates in northern direction are studied. The geodynamic model is developed, on which the basic moving force in tectonics of plates is a gravitational influence of a moveable core of the Earth on all layers of the mantle, and also on blocks of the crust and lithosphere plates. In a base of all tectonic and geological reorganizations the mechanism of the forced relative oscillations and swings of the core and the mantle of the Earth in various time scales, including geological timescale lays. 1 Mechanism of formation and changes of the pear-shaped form of the Earth. According to developed geodynamic model a pear-shaped form of planets is not their given property for all time (as believed before scientists), and is the dynamic response to the slow forced relative displacements of the core and mantle [1]. Than more a relative displacement of the core and mantle (eccentricity of the core in some geology epoch), is especially clearly expressed pear-shaped form. The planet Mars possesses a big pear-shaped form and by our estimations the core of this planet is displaced in northern direction (to latitude in approximately 60° N) on 20-25 km [2]. An eccentricity of the Earth core is less (estimations give displacement about 3-4 km in direction to Brazil [3]) and it pear-shaped form is much less. 2 The phenomenon of asymmetric lengthening of latitude circles of southern and northern hemispheres of

  5. Maternal Control and Sensitivity, Child Gender, and Maternal Education in Relation to Children's Behavioral Outcomes in African American Families

    PubMed Central

    Tamis-LeMonda, Catherine S.; Briggs, Rahil D.; McClowry, Sandra G.; Snow, David L.

    2009-01-01

    This study examined relationships between mother-child interactions and children's behaviors in 119 urban African American mothers and their 6 - 7 year old children. Interactions during a cooking task and a follow-up child clean-up task were videotaped. Principal components analyses of behaviors during the cooking task yielded two factors in mothers (Sensitivity and Control), and three in children (Task Involvement, Responsiveness, and Communicative). Children's negativity during a clean up task was coded and mothers were interviewed about their children's problem behaviors. Parenting sensitivity was associated with positive child behaviors and parenting control was associated with negative child behaviors. Maternal education was associated with greater maternal sensitivity and less control. Child gender predicted their task involvement, responsiveness, communicativeness, negativity during clean-up, and behavior problems; maternal control and sensitivity mediated some of these relations. Findings underscore heterogeneity of African American parenting and factors that promote positive parenting and children's behavioral adjustment in early childhood. PMID:20161193

  6. The Prevalence of and Factors Associated with Alcohol-Related Problems in a Community Sample of African American Women

    PubMed Central

    Elifson, Kirk W.

    2016-01-01

    Purpose. This study examines the prevalence of alcohol-related problems, the factors underlying these problems, and whether or not there is evidence of syndemic effects in a community population of southern, urban African American women. Methods. Questionnaire-based interviews were conducted with 817 women, all African American, from 80 targeted census block groups in Atlanta, Georgia. Results. Most of the alcohol users (67.8%) experienced at least one problem as a result of their alcohol (ab)use, with most women experiencing two or more such problems. Eight factors were found to be associated with experiencing more alcohol problems: being aged 30 or older, having had no recent health insurance, lower levels of educational attainment, self-identifying as lesbian or bisexual, experiencing greater amounts of childhood maltreatment, greater impulsivity, perceiving one's local community or neighborhood to be unsafe, and having a larger number of criminally involved friends. Conclusions. Drinking-related problems were prevalent in this population. Numerous factors underlie the extent to which African American women experienced problems resulting from their alcohol use. There is strong evidence of syndemic-type effects influencing drinking problems in this population, and future efforts to reduce the negative impact of alcohol (ab)use ought to consider the adoption of programs using a syndemics' theory approach. PMID:27752388

  7. An Examination of Factors Related to the Academic Performance of African-American College Students

    ERIC Educational Resources Information Center

    Wylie, D'Errico M.

    2012-01-01

    The purpose of this study was to identify factors that were predictive of academic performance of college students at Historically Black Colleges/Universities (HBCUs). The variables of interest included: seating choice, self-esteem, anxiety, stress and study habits. The sample consisted of 201 African-American undergraduate students. Participants…

  8. Responding to AIDS-Related Bereavement in the South African Context

    ERIC Educational Resources Information Center

    Demmer, Craig

    2007-01-01

    AIDS continues to be a death sentence for many individuals living in South Africa where it remains the leading cause of death. Little is currently known about what it is like to experience the loss of a loved one to AIDS from the South African perspective and how to assist individuals who are living in a context vastly different from similarly…

  9. Friendships Influence Hispanic Students' Implicit Attitudes toward White Non-Hispanics Relative to African Americans

    ERIC Educational Resources Information Center

    Aberson, Christopher L.; Porter, Michael K.; Gaffney, Amber M.

    2008-01-01

    This study examined the role of Hispanic students' friendships with White non-Hispanics (n-Hs) and African Americans (AAs) in predicting implicit and explicit prejudices toward these groups. Participants (N = 73) completed implicit and explicit attitude measures and a friendship questionnaire. Friendships were associated with implicit attitudes…

  10. The Relation among Parental Factors and Achievement of African American Urban Youth

    ERIC Educational Resources Information Center

    Wilson, Clancie Mavello

    2009-01-01

    Research has suggested that low socioeconomic status is a major factor in diminishing academic achievement of African American urban youth; however, there are other factors influencing students' achievement. To examine the other factors that contribute to academic achievement, this study investigated a sample of 60 low-resource middle school…

  11. Lexicon size and its relation to foot preference in the African grey parrot (Psittacus erithacus).

    PubMed

    Snyder, P J; Harris, L J

    1997-06-01

    To study footedness in parrots, an international survey of parrot owners was conducted. Responses were obtained from 524 individuals, including 70 owners of African Grey parrots (all animals > or = 10 months old). All respondents were given a 10-item questionnaire and a standard method for testing foot preference in their pets, and they were asked to count the number of separate words in their pets' lexicons of human speech sounds. Right-footed African Greys (N = 36) had significantly larger lexicons than left-footed African Greys (N = 34; P = 0.01). This difference could not be accounted for by group differences in training efforts or socialization/housing with conspecifics. A non-significant trend in the same direction was found in a comparison sample of Amazon parrots, although these genera are less adept than African Greys at learning human speech sounds. Other investigators have provided convincing evidence of lateralization, in the avian brain, for the analysis and memory of differing types of stimuli. In addition, there appears to be preferential left hypserstriatal activation for long-term memory consolidation. Our results suggest a relationship between lateral asymmetry for motor preference and asymmetric CNS mediation of a 'higher cognitive' function (i.e. the categorization and long-term mnestic processing of human speech sound.

  12. A History of Black and Brown: Chicana/o-African American Cultural and Political Relations

    ERIC Educational Resources Information Center

    Alvarez, Luis; Widener, Daniel

    2008-01-01

    Rather than assume that ethnicity or race necessarily marks the edges of one's culture or politics, the contributors to this dossier highlight the messy, blurry, and often contradictory relationships that arise when Chicana/os and African Americans engage one another. The essays explore the complicated mix of cooperation and conflict that…

  13. Sex-Related HIV/AIDS Prevention among African American College Students: Issues for Preventive Counseling.

    ERIC Educational Resources Information Center

    Braithwaite, Ronald; Stephens, Torrance; Sumpter-Gaddist, Bambi W.; Murdaugh, Henry; Taylor, Sandra; Braithwaite, Kisha

    1998-01-01

    Examines condom use during oral and anal sex among 1593 African-American college undergraduates. Findings suggest a high level of concordance between men and women on several measures. However, female participants were more likely to use condoms during oral and anal sex than were males. (Author/MKA)

  14. Civic Engagement in Relation to Outcome Expectations among African American Young Adults

    ERIC Educational Resources Information Center

    Chung, He Len; Probert, Stephanie

    2011-01-01

    The present study examined civic engagement--volunteering and political activism--among 129 African American young adults from an urban community. The proposed model considered factors that motivate young adults to participate in civic activities as well as barriers that might inhibit involvement. Drawing upon social cognitive theory, this study…

  15. Understanding the findings of resilience-related research for fostering the development of African American adolescents.

    PubMed

    Barrow, Frederica H; Armstrong, Mary I; Vargo, Amy; Boothroyd, Roger A

    2007-04-01

    African American youth face a number of challenges to prosocial development that the majority of American youth never encounter. Despite this, the research clearly documents that African American youth often are resilient in the face of these challenges. This article explores various factors associated with resilience in African American children and their implications for practitioners. An ecologic framework described by Bronfenbrenner is used as an organizing framework for understanding interventions at the micro-, mezzo-, and exo-system levels. In this article, the importance of identity formation, maintenance of social networks, and exposure to safe and supportive environments is expressed in conjunction with recommendations for practitioners. Practitioners are encouraged to stress the promotion of ethnic and racial identity and self-efficacy with the youth and their family and the involvement of the youth and family in meaningful activities through local community centers, schools, churches, and other organizations serving youth. A case study of an African American girl, from age 16 into adulthood and motherhood, is presented to illustrate the interplay between protective and risk factors.

  16. Factors Related to College Going Self-Efficacy among Urban African American High School Students

    ERIC Educational Resources Information Center

    McKechnie, Jessica Diaz

    2012-01-01

    This study examined the relationship between college-going self-efficacy and high school students' perceived levels of achievement goal orientations (mastery-approach, performance-approach, performance-avoidance), vocational identity, need for occupational information, and barriers to occupational goals for a sample of African American urban…

  17. The Effects of Check & Connect on the School-Related Violent Behaviors of African American Females

    ERIC Educational Resources Information Center

    Seaton, Angela T.

    2010-01-01

    This study assessed the effects of a modified version of Check & Connect, a comprehensive student engagement intervention, on the attendance, behavior, and academic performance of secondary African American females with violent and aggressive behavior problems. In addition, the Student Engagement Instrument (SEI) was used to assess cognitive…

  18. Developmental and ethnic issues experienced by emerging adult African American women related to developing a mature love relationship.

    PubMed

    Tyson, Sheryl Y

    2012-01-01

    This qualitative study explored perspectives of emerging adult African American women on the development of mature love relationships. Inductive analysis of focus group interviews, conducted with a purposive sample of 31 African American women, yielded themes related to relationship goals and characteristics, and interpersonal and societal challenges to finding the right partner and developing a mature love relationship. Core categories that emerged from analysis of the discussions were (1) age and relationship goal differences within the emerging adult group, (2) mature love relationship goals and characteristics, (3) interpersonal obstacles to finding the right partner, and (4) societal obstacles to finding the right partner. Two approaches-black womanist/feminist thought (Collins, 2000 ; Walker, 1983 ) and relationship maturity theory (Paul & White, 1990 )-were then combined to explain the influence of historic and contemporary interpersonal and societal factors on developmental and ethnic issues that challenge positive gender identity formation, hasten intimacy maturity, and hinder the development of mature love relationships among emerging adult African American women. For these women, premature responsibility, especially early caregiver burden, was related to the early development of intimacy capacity and the desire for a mature love relationship, to be protected, and to have someone to help carry the load. Interracial dating, negative stereotypic images of African American women, and even positive images of enduring black love relationships posed difficult challenges to positive identity formation and intimacy maturity. A primary challenge was to counteract negative stereotypic images, so that they could develop their own self-identities as women and as relationship partners. PMID:22224965

  19. APOL1 Risk Alleles Are Associated with Exaggerated Age-Related Changes in Glomerular Number and Volume in African-American Adults: An Autopsy Study.

    PubMed

    Hoy, Wendy E; Hughson, Michael D; Kopp, Jeffrey B; Mott, Susan A; Bertram, John F; Winkler, Cheryl A

    2015-12-01

    APOL1 genetic variants contribute to kidney disease in African Americans. We assessed correlations between APOL1 profiles and renal histological features in subjects without renal disease. Glomerular number (N glom) and mean glomerular volume (V glom) were measured by the dissector/fractionator method in kidneys of African-American and non-African-American adults without renal disease, undergoing autopsies in Jackson, Mississippi. APOL1 risk alleles were genotyped and the kidney findings were evaluated in the context of those profiles. The proportions of African Americans with none, one, and two APOL1 risk alleles were 38%, 43%, and 19%, respectively; 38% of African Americans had G1 allele variants and 31% of African Americans had G2 allele variants. Only APOL1-positive African Americans had significant reductions in N glom and increases in V glom with increasing age. Regression analysis predicted an annual average loss of 8834 (P=0.03, sex adjusted) glomeruli per single kidney over the first 38 years of adult life in African Americans with two risk alleles. Body mass index above the group medians, but below the obesity definition of ≥ 30 kg/m(2), enhanced the expression of age-related changes in N glom in African Americans with either one or two APOL1 risk alleles. These findings indicate that APOL1 risk alleles are associated with exaggerated age-related nephron loss, probably decaying from a larger pool of smaller glomeruli in early adult life, along with enlargement of the remaining glomeruli. These phenomena might mark mechanisms of accentuated susceptibility to kidney disease in APOL1-positive African Americans.

  20. (Im)migrations, Relations, and Identities of African Peoples: Toward an Endarkened Transnational Feminist Praxis in Education

    ERIC Educational Resources Information Center

    Okpalaoka, Chinwe L.; Dillard, Cynthia B.

    2012-01-01

    This article focuses on the sense of what an "African" (American) identity could mean when viewed through the processes of migrations and fluid identities of contemporary African immigrant children as they interact with their African (Americans) peers in schools. The purpose of this article is to use data from a study of West African immigrant…

  1. On the relations between cratonic lithosphere thickness, plate motions, and basal drag

    USGS Publications Warehouse

    Artemieva, I.M.; Mooney, W.D.

    2002-01-01

    An overview of seismic, thermal, and petrological evidence on the structure of Precambrian lithosphere suggests that its local maximum thickness is highly variable (140-350 km), with a bimodal distribution for Archean cratons (200-220 km and 300-350 km). We discuss the origin of such large differences in lithospheric thickness, and propose that the lithospheric base can have large depth variations over short distances. The topography of Bryce Canyon (western USA) is proposed as an inverted analog of the base of the lithosphere. The horizontal and vertical dimensions of Archean cratons are strongly correlated: larger cratons have thicker lithosphere. Analysis of the bimodal distribution of lithospheric thickness in Archean cratons shows that the "critical" surface area for cratons to have thick (>300 km) keels is >6-8 ?? 106 km2 . Extrapolation of the linear trend between Archean lithospheric thickness and cratonic area to zero area yields a thickness of 180 km. This implies that the reworking of Archean crust should be accompanied by thinning and reworking of the entire lithospheric column to a thickness of 180 km in accord with thickness estimates for Proterozoic lithosphere. Likewise, extrapolation of the same trend to the size equal to the total area of all Archean cratons implies that the lithospheric thickness of a hypothesized early Archean supercontinent could have been 350-450 km decreasing to 280-400 km for Gondwanaland. We evaluate the basal drag model as a possible mechanism that may thin the cratonic lithosphere. Inverse correlations are found between lithospheric thickness and (a) fractional subduction length and (b) the effective ridge length. In agreement with theoretical predictions, lithospheric thickness of Archean keels is proportional to the square root of the ratio of the craton length (along the direction of plate motion) to the plate velocity. Large cratons with thick keels and low plate velocities are less eroded by basal drag than small

  2. Mantle-derived peridotites in southwestern Oregon: relation to plate tectonics.

    PubMed

    Medaris, L G; Dott, R H

    1970-09-01

    A group of peridotites in southwestern Oregon contains high-pressure mineral assemblages reflecting recrystallization at high temperatures (1100 degrees to 1200 degrees C) over a range of pressure decreasing from 19 to 5 kilobars. It is proposed that the peridotites represent upper-mantle material brought from depth along the ancestral Gorda-Juan de Fuca ridge system, transported eastward by the spreading Gorda lithosphere plate, and then emplaced by thrust-faulting in the western margin of the Cordillera during late Mesozoic time.

  3. Ridge push, mantle plumes and the speed of the Indian plate

    NASA Astrophysics Data System (ADS)

    Eagles, Graeme; Wibisono, Affelia D.

    2013-08-01

    The buoyancy of lithospheric slabs in subduction zones is widely thought to dominate the torques driving plate tectonics. In late Cretaceous and early Paleogene times, the Indian plate moved more rapidly over the mantle than freely subducting slabs sink within it. This signal event has been attributed to arrival of the Deccan-Réunion mantle plume beneath the plate, but it is unknown in which proportions the plume acted to alter the balance of existing plate driving torques and to introduce torques of its own. Our plate kinematic analysis of the Mascarene Basin yields a detailed Indian plate motion history for the period 89-60 Ma. Plate speed initially increases steadily until a pronounced acceleration in the period 68-64 Ma, after which it abruptly returns to values much like those beforehand. This pattern is unlike that suggested to result from the direct introduction of driving forces by the arrival of a thermal plume at the base of the plate. A simple analysis of the gravitational force related to the Indian plate's thickening away from its boundary with the African plate suggests instead that the sudden acceleration and deceleration may be related to uplift of part of that boundary during a period when it was located over the plume head. In this instance, torques related to plate accretion and subduction may have contributed in similar proportions to drive plate motion.

  4. Differences in Health-Related Behaviors and Body Mass Index Risk Categories in African American Women in College

    PubMed Central

    Stanziano, Damian C.; Butler-Ajibade, Phoebe

    2011-01-01

    Objective To determine if differences in health-related behaviors (diet and physical activity) exist in African American college women based on body mass index (BMI) risk categories. Methods One hundred eighty-six African American women (age, 19.5 ± 2.5 y) in college were surveyed using the modified National College Health Risk Behavior Survey. Data regarding demographics, weight loss history/methods, food choices, and physical activity frequency were compared for obese (BMI ≥30, n = 30), overweight (25 ≤ BMI < 30, n = 45), and normal-weight (BMI <25, n = 111) groups. Data were analyzed using multiple 2-way analyses of variance. Results No differences in food choices were determined between the groups. The overweight and obese groups were more likely than the normal-weight group to have used healthy modalities such as diet and/or exercise to try to lose weight instead of unhealthy methods such as laxatives and diet pills. The overweight group reported more vigorous aerobic training and strength training workouts than the normal-weight group. Conclusions Food selection and activity frequency are not enough to differentiate African American women in different BMI categories. Other factors may contribute to obesity such as food portion sizes, genetics, and/or intensity of physical activities. PMID:21329240

  5. Variation of b and p values from aftershocks sequences along the Mexican subduction zone and their relation to plate characteristics

    NASA Astrophysics Data System (ADS)

    Ávila-Barrientos, L.; Zúñiga, F. R.; Rodríguez-Pérez, Q.; Guzmán-Speziale, M.

    2015-11-01

    Aftershock sequences along the Mexican subduction margin (between coordinates 110ºW and 91ºW) were analyzed by means of the p value from the Omori-Utsu relation and the b value from the Gutenberg-Richter relation. We focused on recent medium to large (Mw > 5.6) events considered susceptible of generating aftershock sequences suitable for analysis. The main goal was to try to find a possible correlation between aftershock parameters and plate characteristics, such as displacement rate, age and segmentation. The subduction regime of Mexico is one of the most active regions of the world with a high frequency of occurrence of medium to large events and plate characteristics change along the subduction margin. Previous studies have observed differences in seismic source characteristics at the subduction regime, which may indicate a difference in rheology and possible segmentation. The results of the analysis of the aftershock sequences indicate a slight tendency for p values to decrease from west to east with increasing of plate age although a statistical significance is undermined by the small number of aftershocks in the sequences, a particular feature distinctive of the region as compared to other world subduction regimes. The b values show an opposite, increasing trend towards the east even though the statistical significance is not enough to warrant the validation of such a trend. A linear regression between both parameters provides additional support for the inverse relation. Moreover, we calculated the seismic coupling coefficient, showing a direct relation with the p and b values. While we cannot undoubtedly confirm the hypothesis that aftershock generation depends on certain tectonic characteristics (age, thickness, temperature), our results do not reject it thus encouraging further study into this question.

  6. Analysis of batch-related influences on injection molding processes viewed in the context of electro plating quality demands

    NASA Astrophysics Data System (ADS)

    Siepmann, Jens P.; Wortberg, Johannes; Heinzler, Felix A.

    2016-03-01

    The injection molding process is mandatorily influenced by the viscosity of the material. By varying the material batch the viscosity of the polymer changes. For the process and part quality the initial conditions of the material in addition to the processing parameters define the process and product quality. A high percentage of technical polymers processed in injection molding is refined in a follow-up production step, for example electro plating. Processing optimized for electro plating often requires avoiding high shear stresses by using low injection speed and pressure conditions. Therefore differences in the material charges' viscosity occur especially in the quality related low shear rate area. These differences and quality related influences can be investigated by high detail rheological analysis and process simulation based on adapted material describing models. Differences in viscosity between batches can be detected by measurements with high-pressure-capillary-rheometers or oscillatory rheometers for low shear rates. A combination of both measurement techniques is possible by the Cox-Merz-Relation. The detected differences in the rheological behavior of both charges are summarized in two material behavior describing model approaches and added to the simulation. In this paper the results of processing-simulations with standard filling parameters are presented with two ABS charges. Part quality defining quantities such as temperature, pressure and shear stress are investigated and the influence of charge variations is pointed out with respect to electro plating quality demands. Furthermore, the results of simulations with a new quality related process control are presented and compared to the standard processing.

  7. East African Rift Valley, Kenya

    NASA Technical Reports Server (NTRS)

    1990-01-01

    This rare, cloud free view of the East African Rift Valley, Kenya (1.5N, 35.5E) shows a clear view of the Turkwell River Valley, an offshoot of the African REift System. The East African Rift is part of a vast plate fracture which extends from southern Turkey, through the Red Sea, East Africa and into Mozambique. Dark green patches of forests are seen along the rift margin and tea plantations occupy the cooler higher ground.

  8. Space Use of African Wild Dogs in Relation to Other Large Carnivores

    PubMed Central

    Darnell, Angela M.; Graf, Jan A.; Somers, Michael J.; Slotow, Rob; Szykman Gunther, Micaela

    2014-01-01

    Interaction among species through competition is a principle process structuring ecological communities, affecting behavior, distribution, and ultimately the population dynamics of species. High competition among large African carnivores, associated with extensive diet overlap, manifests in interactions between subordinate African wild dogs (Lycaon pictus) and dominant lions (Panthera leo) and spotted hyenas (Crocuta crocuta). Using locations of large carnivores in Hluhluwe-iMfolozi Park, South Africa, we found different responses from wild dogs to their two main competitors. Wild dogs avoided lions, particularly during denning, through a combination of spatial and temporal avoidance. However, wild dogs did not exhibit spatial or temporal avoidance of spotted hyenas, likely because wild dog pack sizes were large enough to adequately defend their kills. Understanding that larger carnivores affect the movements and space use of other carnivores is important for managing current small and fragmented carnivore populations, especially as reintroductions and translocations are essential tools used for the survival of endangered species, as with African wild dogs. PMID:24896638

  9. Space use of African wild dogs in relation to other large carnivores.

    PubMed

    Darnell, Angela M; Graf, Jan A; Somers, Michael J; Slotow, Rob; Szykman Gunther, Micaela

    2014-01-01

    Interaction among species through competition is a principle process structuring ecological communities, affecting behavior, distribution, and ultimately the population dynamics of species. High competition among large African carnivores, associated with extensive diet overlap, manifests in interactions between subordinate African wild dogs (Lycaon pictus) and dominant lions (Panthera leo) and spotted hyenas (Crocuta crocuta). Using locations of large carnivores in Hluhluwe-iMfolozi Park, South Africa, we found different responses from wild dogs to their two main competitors. Wild dogs avoided lions, particularly during denning, through a combination of spatial and temporal avoidance. However, wild dogs did not exhibit spatial or temporal avoidance of spotted hyenas, likely because wild dog pack sizes were large enough to adequately defend their kills. Understanding that larger carnivores affect the movements and space use of other carnivores is important for managing current small and fragmented carnivore populations, especially as reintroductions and translocations are essential tools used for the survival of endangered species, as with African wild dogs. PMID:24896638

  10. African Great Apes Are Naturally Infected with Roseoloviruses Closely Related to Human Herpesvirus 7

    PubMed Central

    Lavergne, Anne; Donato, Damien; Gessain, Antoine; Niphuis, Henk; Nerrienet, Eric; Verschoor, Ernst J.

    2014-01-01

    ABSTRACT Primates are naturally infected with herpesviruses. During the last 15 years, the search for homologues of human herpesviruses in nonhuman primates allowed the identification of numerous viruses belonging to the different herpesvirus subfamilies and genera. No simian homologue of human herpesvirus 7 (HHV7) has been reported to date. To investigate the putative existence of HHV7-like viruses in African great apes, we applied the consensus-degenerate hybrid oligonucleotide primers (CODEHOP) program-mediated PCR strategy to blood DNA samples from the four common chimpanzee subspecies (Pan troglodytes verus, P. t. ellioti, P. t. troglodytes, and P. t. schweinfurthii), pygmy chimpanzees (Pan paniscus), as well as lowland gorillas (Gorilla gorilla gorilla). This study led to the discovery of a novel roseolovirus close to HHV7 in each of these nonhuman primate species and subspecies. Generation of the partial glycoprotein B (1,111-bp) and full-length DNA polymerase (3,036/3,042-bp) gene sequences allowed the deciphering of their evolutionary relationships. Phylogenetic analyses revealed that HHV7 and its African great ape homologues formed well-supported monophyletic lineages whose topological resemblance to the host phylogeny is suggestive of virus-host codivergence. Notably, the evolutionary branching points that separate HHV7 from African great ape herpesvirus 7 are remarkably congruent with the dates of divergence of their hosts. Our study shows that African great apes are hosts of human herpesvirus homologues, including HHV7 homologues, and that the latter, like other DNA viruses that establish persistent infections, have cospeciated with their hosts. IMPORTANCE Human herpesviruses are known to possess simian homologues. However, surprisingly, none has been identified to date for human herpesvirus 7 (HHV7). This study is the first to describe simian homologues of HHV7. The extensive search performed on almost all African great ape species and subspecies, i

  11. Propagation of SH waves in a piezoelectric/piezomagnetic plate: Effects of interfacial imperfection couplings and the related physical mechanisms

    NASA Astrophysics Data System (ADS)

    Wei, Hong-Xing; Li, Yong-Dong; Xiong, Tao; Guan, Yong

    2016-09-01

    The problem of dispersive SH wave in a piezoelectric/piezomagnetic plate that contains an imperfect interface is considered in the present work. An imperfection coupling model is adopted to describe the magnetic, electric and mechanical imperfections on the interface. A transcendental dispersion equation is derived and numerically solved to get the phase velocity. The validity of the numerical procedure is verified in a degenerated case. The effects of the coupled interfacial imperfections on the dispersion behavior of SH waves are discussed in detail and the related underlying physical mechanisms are explained.

  12. Disentangling the effects of race and SES on arthritis-related symptoms, coping, and well-being in African American and White women.

    PubMed

    McIlvane, J M

    2007-09-01

    This study examined both unique and interactive effects of race and socioeconomic status (SES) on arthritis-related symptoms, coping, and well-being in African American and White women. Participants included 77 African American and 98 White women, aged 45 to 90, who completed structured, face-to-face interviews. A series of 2 x 2 MANCOVAs examined race (African American, White) and SES (high/low education or high/low occupational status) differences in arthritis-related symptoms, coping, and well-being. African Americans used more religious coping, wishful-thinking, seeking social support, and emotional expression than Whites. Individuals with low SES reported worse arthritis-related symptoms, poorer well-being, and greater use of coping strategies that tend to be maladaptive. Race x SES interactions revealed higher depressive symptoms in African Americans with low versus high education and coping differences in African Americans with low versus high occupational status; however differences in depressive symptoms and coping based on SES were not evident for Whites. Results demonstrate unique and interactive race and SES differences for arthritis-related symptoms, coping, and well-being showing the complexity of race and SES in the realm of physical and mental health.

  13. Self Views of African American Youth are Related to the Gender Stereotypes and Academic Attributions of Their Mothers.

    PubMed

    Rowley, Stephanie; Kurtz-Costes, Beth; Rouland, Karmen

    2013-01-01

    We examined relations among African American mothers' (N = 392) stereotypes about gender differences in mathematics, science, and reading performance, parents' attributions about their children's academic successes and failures, and their seventh and eighth grade children's academic self-views (domain-specific ability attributions and self-concept). Parents' stereotypes about gender differences in abilities were related to their ability attributions for their children's successes and failures within academic domains. Mothers' attributions, in turn, were related to children's attributions, particularly among girls. Mothers' attributions of their children's successes to domain-specific ability were related to the self-concepts of daughters, and failure attributions were related to domain-specific self-concepts of sons. The influences of parents' beliefs on young adolescents' identity beliefs are discussed.

  14. Self Views of African American Youth are Related to the Gender Stereotypes and Academic Attributions of Their Mothers

    PubMed Central

    Rowley, Stephanie; Kurtz-Costes, Beth; Rouland, Karmen

    2012-01-01

    We examined relations among African American mothers’ (N = 392) stereotypes about gender differences in mathematics, science, and reading performance, parents’ attributions about their children’s academic successes and failures, and their seventh and eighth grade children’s academic self-views (domain-specific ability attributions and self-concept). Parents’ stereotypes about gender differences in abilities were related to their ability attributions for their children’s successes and failures within academic domains. Mothers’ attributions, in turn, were related to children’s attributions, particularly among girls. Mothers’ attributions of their children’s successes to domain-specific ability were related to the self-concepts of daughters, and failure attributions were related to domain-specific self-concepts of sons. The influences of parents’ beliefs on young adolescents’ identity beliefs are discussed. PMID:23878519

  15. Possible microplate generation at RRR triple junctions due to the non-circular finite motion of plates relative to each other

    NASA Astrophysics Data System (ADS)

    Cronin, V. S.

    2012-12-01

    First generation ideas of the kinematic stability of triple junctions lead to the common belief that the geometry of ridge-ridge-ridge (RRR) triple junctions remains constant over time under conditions of symmetric spreading. Given constant relative motion between each plate pair -- that is, the pole of plate relative motion is fixed to both plates in each pair during finite motion, as assumed in many accounts of plate kinematics -- there would be no boundary mismatch at the triple junction and no apparent kinematic reason why a microplate might develop there. But if, in a given RRR triple junction, the finite motion of one plate as observed from the other plate is not circular (as is generally the case, given the three-plate problem of plate kinematics), the geometry of the ridges and the triple junction will vary with time (Cronin, 1992, Tectonophys 207, 287-301). To explore the possible consequences of non-circular finite motion between plates at an RRR triple junction, a simple model was coded based on the cycloid finite-motion model (e.g., Cronin, 1987, Geology 15, 1006-1009) using NNR-MORVEL56 velocities for individual plates (Argus et al., 2011, G3 12, doi: 10.1029/2011GC003751). Initial assumptions include a spherical Earth, symmetric spreading, and constant angular velocities during the modeled finite time interval. The assumed-constant angular velocity vectors constitute a reference frame for observing finite plate motion. Typical results are [1] that the triple junction migrates relative to a coordinate system fixed to the angular-velocity vectors, [2] ridge axes rotates relative to each other, and [3] a boundary mismatch develops at the synthetic triple junction that might result in microplate nucleation. In a model simulating the Galapagos triple junction between the Cocos, Nazca and Pacific plates whose initial state did not include the Galapagos microplate, the mismatch gap was as much as ~3.4 km during 3 Myr of model displacement (see figure). The

  16. Phylogenetic relations of humans and African apes from DNA sequences in the Psi eta-globin region

    SciTech Connect

    Miyamoto, M.M.; Slightom, J.L.; Goodman, M.

    1987-10-16

    Sequences from the upstream and downstream flanking DNA regions of the Psi eta-globin locus in Pan troglodytes (common chimpanzee), Gorilla gorilla (gorilla), and Pongo pygmaeus (orangutan, the closest living relative to Homo, Pan, and Gorilla) provided further data for evaluating the phylogenetic relations of humans and African apes. These newly sequenced orthologs (an additional 4.9 kilobase pairs (kbp) for each species) were combined with published Psi eta-gene sequences and then compared to the same orthologous stretch (a continuous 7.1-kbp region) available for humans. Phylogenetic analysis of these nucleotide sequences by the parsimony method indicated (i) that human and chimpanzee are more closely related to each other than either is to gorilla and (ii) that the slowdown in the rate of sequence evolution evident in higher primates is especially pronounced in humans. These results indicate that features unique to African apes (but not to humans) are primitive and that even local molecular clocks should be applied with caution.

  17. Perceived HIV-related sexual risks and prevention practices of African American women in the southeastern United States.

    PubMed

    Timmons, S M; Sowell, R L

    1999-01-01

    African American women in the southeastern United States constitute the fastest growing segment of those infected with the human immunodeficiency virus (HIV). Little data exist about the relationships between HIV infection risks and preventive practices. In this article, we describe a focus group investigation of how HIV-related sexual risks are perceived by 19 heterosexual African American women, ages 18 to 44. Data were analyzed and interpreted using content analysis, where key ideas, words, and phrases were grouped based on their relation to the purpose of the study. Four themes were revealed: "a man will be a man," inconsistent and/or no condom use, safe relationships, and racism and discrimination. Perceived safety within relationships mediated both perceptions of HIV-related risks and sexual practices. In light of beliefs about the riskiness of sex with high-risk partners, fear of HIV, and the importance of self love in minimizing HIV infection risks, the women continued to practice unsafe sexual behaviors. Results indicate that women perceive themselves as victims in society and that this perception limits their propensity to take action to protect themselves from HIV. Successful HIV infection prevention interventions need to address negative social and economic factors that define the context of many women's lives.

  18. Perceived HIV-related sexual risks and prevention practices of African American women in the southeastern United States.

    PubMed

    Timmons, S M; Sowell, R L

    1999-01-01

    African American women in the southeastern United States constitute the fastest growing segment of those infected with the human immunodeficiency virus (HIV). Little data exist about the relationships between HIV infection risks and preventive practices. In this article, we describe a focus group investigation of how HIV-related sexual risks are perceived by 19 heterosexual African American women, ages 18 to 44. Data were analyzed and interpreted using content analysis, where key ideas, words, and phrases were grouped based on their relation to the purpose of the study. Four themes were revealed: "a man will be a man," inconsistent and/or no condom use, safe relationships, and racism and discrimination. Perceived safety within relationships mediated both perceptions of HIV-related risks and sexual practices. In light of beliefs about the riskiness of sex with high-risk partners, fear of HIV, and the importance of self love in minimizing HIV infection risks, the women continued to practice unsafe sexual behaviors. Results indicate that women perceive themselves as victims in society and that this perception limits their propensity to take action to protect themselves from HIV. Successful HIV infection prevention interventions need to address negative social and economic factors that define the context of many women's lives. PMID:10889636

  19. Evaluation of Relative Sensitivity of SAW and Flexural Plate Wave Devices for Atmospheric Sensing

    NASA Technical Reports Server (NTRS)

    White, Richard M.; Black, Justin; Chen, Bryan

    1998-01-01

    The objective of this project is to evaluate the suitability of the ultrasonic flexural plate wave (FPW) device as the detector in a gas chromatograph (GC). Of particular interest is the detection of nitrous oxide (N2O). From experimental results we conclude analyte detection is achieved through two mechanisms: changes in gas density, and mass loading of the device membrane due to the sorption of gas molecules. Reducing the dead volume of the FPW chamber increased the FPW response. A comparison of the FPW response to that of the surface acoustic wave (SAW) detector provided with the GC (made by MSI, Microsensor Technologies, Inc.), shows that for unseparated N2O in N2, the FPW exhibits a sensitivity that is at least 550 times greater than that of the SAW device. A Porapak Q column was found to separate N2O from its carrier gas, N2 or He. With the Porapak Q column, a coated FPW detected 1 ppm N2O in N2 or He, with a response magnitude of 7 Hz. A coated SAW exhibited a response of 25 Hz to pure N2O. The minimal detectable N2O concentrations of the sensors were not evaluated.

  20. Environmental, policy, and cultural factors related to physical activity in African American women.

    PubMed

    Richter, Donna L; Wilcox, Sara; Greaney, Mary L; Henderson, Karla A; Ainsworth, Barbara E

    2002-01-01

    Six focus groups were conducted in South Carolina with African American women (n = 42) aged 19-51 years to identify factors that influence physical activity. Transcripts were analyzed using NUD*IST. Cultural influences were seen as more important in determining the type of physical activity than its level. Barriers to and enablers of physical activity were identified in the social and physical environments, as were policy issues affecting physical activity in the community and at the work site. Potential community and work site interventions were suggested. Child care and monetary costs were frequently cited as barriers to physical activity. PMID:12487143

  1. Iberian plate kinematics: A jumping plate boundary between Eurasia and Africa

    USGS Publications Warehouse

    Srivastava, S.P.; Schouten, Hans; Roest, W.R.; Klitgord, Kim D.; Kovacs, L.C.; Verhoef, J.; Macnab, R.

    1990-01-01

    THE rotation of Iberia and its relation to the formation of the Pyrenees has been difficult to decipher because of the lack of detailed sea-floor spreading data, although several models have been proposed1-7. Here we use detailed aeromagnetic measurements from the sea floor offshore of the Grand Banks of Newfoundland to show that Iberia moved as part of the African plate from late Cretaceous to mid-Eocene time, with a plate boundary extending westward from the Bay of Biscay. When motion along this boundary ceased, a boundary linking extension in the King's Trough to compression along the Pyrenees came into existence. Finally, since the late Oligocene, Iberia has been part of the Eurasian plate, with the boundary between Eurasia and Africa situated along the Azores-Gibraltar fracture zone.

  2. Religious socialization in African American families: the relative influence of parents, grandparents, and siblings.

    PubMed

    Gutierrez, Ian A; Goodwin, Lucas J; Kirkinis, Katherine; Mattis, Jacqueline S

    2014-12-01

    The family is the principal context for religious and spiritual socialization. Although religion remains a central force in the lives of most African Americans, research has failed to explore the role and impact of family on religious socialization within this population. This study addresses that gap in the literature by (1) exploring adults' perceptions of the influence of their parents, grandparents, and siblings on their religious and spiritual lives, and (2) examining the extent to which those perceptions are associated with subjective religiosity, subjective spirituality, religious importance, and commitment to religious socialization among a community sample of urban-residing African American adults in the Midwest and Northeast (N = 319). Findings revealed that, on average, parents, grandparents, and siblings positively influenced adults' religious commitment and values. However, mothers had the greatest positive influence on these outcomes. Religious commitment and values were differentially associated with family members as a function of the generation and gender of the family member. The implications of these findings are discussed.

  3. AIDS-Related Stigmas and Safe-Sex Practices of African-American College Students: A Pilot Study.

    ERIC Educational Resources Information Center

    Chandler, Donald S., Jr.

    This study examined the safe-sex practices of African-American colleges students in light of culturally-specific beliefs that stigmatize Acquired Immune Deficiency Syndrome (AIDS) in the African-American community. A total of 21 self-selected, sexually-active African-American students (15 females and 6 males) aged 18-22 completed the AIDS…

  4. African-American Male Student Perceptions about Factors Related to Why Black Boys Drop out of Secondary School

    ERIC Educational Resources Information Center

    Edwards, Anntwanique DeVonne

    2012-01-01

    African-American males are overwhelmingly represented in the nation's dropout rates. Dropping out of school has serious social and economic consequences for our society. The dropout rate is overwhelmingly represented by African-American male students, but limited attention is given to student voice. This study examines African-American male…

  5. The burden of natural and technological disaster-related mortality on gross domestic product (GDP) in the WHO African region.

    PubMed

    Kirigia, Joses M; Sambo, Luis G; Aldis, W; Mwabu, Germano M

    2002-01-01

    The WHO Africa region has the highest disaster mortality rate compared to the other five regions of the organization. Those deaths are hypothesized to have significantly negative effect on per capita gross domestic product (GDP). The objective of this study was to estimate the loss in GDP attributable to natural and technological disaster-related mortality in the WHO African Region. We estimated the impact of disaster-related mortality on GDP using double-log econometric model and cross-sectional data (from the UNDP and the World Bank publications) on 45 out of 46 countries in the WHO African Region. The coefficients for capital (K), educational enrolment (EN), life expectancy (LE) and exports (X) had a positive sign; while imports (M) and disaster mortality (DS) were found to impact negatively on GDP. The abovementioned explanatory variables were found to have statistically significant effect on GDP at 5% level in a t-distribution test. Disaster mortality of a single person was found to reduce GDP by US$0.018. We have demonstrated that disaster mortality has a significant negative effect on GDP. Thus, as policy-makers strive to increase GDP through capital investment, export promotion and increase in educational enrolment, they should always recall that investments in strengthening national capacity to mitigate the effects of national disasters expeditiously and effectively shall yield significant economic returns. PMID:17298162

  6. Accelerated plate tectonics.

    PubMed

    Anderson, D L

    1975-03-21

    The concept of a stressed elastic lithospheric plate riding on a viscous asthenosphere is used to calculate the recurrence interval of great earthquakes at convergent plate boundaries, the separation of decoupling and lithospheric earthquakes, and the migration pattern of large earthquakes along an arc. It is proposed that plate motions accelerate after great decoupling earthquakes and that most of the observed plate motions occur during short periods of time, separated by periods of relative quiescence.

  7. Multiple mantle upwellings beneath the Northern East-African Rift System from relative P- and S-wave traveltime tomography

    NASA Astrophysics Data System (ADS)

    Civiero, Chiara; Hammond, James; Goes, Saskia; Fishwick, Stewart; Ahmed, Abdulhakim; Ayele, Atalay; Doubre, Cecile; Goitom, Berhe; Keir, Derek; Kendall, Mike; Leroy, Sylvie; Ogubazghi, Ghebrebrhan; Rumpker, Georg; Stuart, Graham

    2015-04-01

    Mantle plumes have been invoked as the likely cause of East African Rift volcanism and extension. However, the nature of mantle upwelling is debated, with proposed configurations ranging from a single broad plume, the African Superplume, connected to the LLSVP beneath Southern Africa, to one or more distinct lower-mantle sources along the rift. We present a new relative travel-time tomography model that images detailed P- and S- wave velocities from P,S and SKS phases below the northern East-African, Red Sea and Gulf of Aden rift. Data comes from stations that cover the area from Tanzania to Saudi Arabia. The aperture of the integrated dataset allows us to image for the first time structures of ~100 km length scale down to depths of 900 km beneath this region. Our images provide evidence of at least two low-velocity structures with a diameter of ~200 km that continue through the transition zone and into the lower mantle: the first extends to at least 900 km beneath Afar, and a second reaching at least 750 km depth just west of the Main Ethiopian Rift, a region with off-rift volcanism. Taking into account seismic sensitivity to temperature and thermally controlled phase boundary topography, we interpret these features as multiple focused upwellings from below the transition zone with excess temperatures of 100±50 K. The scale of the upwellings is smaller than any of the previously proposed lower mantle plume sources. This suggests the ponding or flow of deep-plume material below the transition zone may be spawning smaller upper-mantle upwellings.

  8. Angular shear plate

    SciTech Connect

    Ruda, Mitchell C.; Greynolds, Alan W.; Stuhlinger, Tilman W.

    2009-07-14

    One or more disc-shaped angular shear plates each include a region thereon having a thickness that varies with a nonlinear function. For the case of two such shear plates, they are positioned in a facing relationship and rotated relative to each other. Light passing through the variable thickness regions in the angular plates is refracted. By properly timing the relative rotation of the plates and by the use of an appropriate polynomial function for the thickness of the shear plate, light passing therethrough can be focused at variable positions.

  9. Marginal deformation of crustal plates as key to crustal motion, crustal spirals, and the driving force

    SciTech Connect

    Wood, B.G.M.

    1986-07-01

    Present plate tectonic models concentrate on compressive- and extensive-type plate margins, often incorporating shear margins as a subtype of compressive margins. However, if a single moving plate is considered, it becomes apparent that the leading edge is a compressive margin, the trailing edge is an extensive margin, and the lateral edges are shear margins. Conversely, if a plate's margin can be recognized by identifying areas of subduction (compression), rifting (extension), and strike slip and buckle folding (shearing), then not only can a plate be identified but its motion can also be inferred. The Pacific plate provides an excellent example. It is bounded by subduction trenches along its west-northwest margin, extension rifts along its east-southeast margin, and shear and buckle-fold complexes along its south-southwest and north-northeast margins. A west-northwest motion is inferred. As other major plates are examined, two striking features are revealed. A west-northwest to northwest motion is consistently identified, and the plates line up end to end forming a northwest-spiraling segmented band encircling the globe. The lateral margins of this band form the well-known Tethyan shear system. The plates comprising this band are of varying sizes and composition, and the extent of deformation along a plate margin is directly related to plate size. The Pacific and Eurasian plates dominate in size and marginal deformation. The tail of this north-spiraling ribbon of crustal plates is deformed in the Southern Hemisphere, most notably in the area of the African, Indian, and Australian plates. Each southern plate has a strong north component of motion as well as a counterclockwise spiraling action. The plates appear to have rotated in response to drag along the southern margin of the Pacific and Eurasian plates.

  10. "She Told Them, Oh That Bitch Got AIDS": Experiences of Multilevel HIV/AIDS-Related Stigma Among African American Women Living with HIV/AIDS in the South.

    PubMed

    Fletcher, Faith; Ingram, Lucy Annang; Kerr, Jelani; Buchberg, Meredith; Bogdan-Lovis, Libby; Philpott-Jones, Sean

    2016-07-01

    African American women bear a disproportionate burden of HIV/AIDS in the United States. Although they constitute only 13% of the US population, African Americans account for nearly 65% of all new HIV infections among American women. In addition, this population suffers comparatively greater adverse health outcomes related to HIV status. African American women living with HIV in the South may be further burdened by HIV/AIDS stigma, which is comparatively more pronounced in this region. To further explore this burden, we used narrative data and the Social Ecological Model to explore how African American women living with HIV in the US South recount, conceptualize, and cope with HIV/AIDS stigma at interpersonal, community, and institutional levels. Our narrative analysis suggests that HIV-positive African American women living in the South are vulnerable to experiences of multilevel HIV stigma in various settings and contexts across multiple domains of life. Stigma subsequently complicated disclosure decisions and made it difficult for women to feel supported in particular social, professional and medical settings that are generally regarded as safe spaces for noninfected individuals. Findings suggest that the debilitating and compounded effect of multilevel HIV/AIDS stigma on HIV-positive African American women in the South warrants closer examination to tailor approaches that effectively address the unique needs of this population. PMID:27410498

  11. Violence exposure and health related risk among African American adolescent female detainees: A strategy for reducing recidivism

    PubMed Central

    Woodson, Kamilah M.; Hives, Courtney; Sanders-Phillips, Kathy

    2010-01-01

    Juvenile crime and violent victimization continue to be significant social problems (Fitzpatrick, Piko, Wright, & LaGory, 2005); in that, adolescents, females in particular, are likely to participate in health related risk behaviors as result of having been victimized or exposed to a violent environment. Specifically, abuse, neglect, sexual molestation, poverty, and witnessing violence are well known risk factors for the development of trauma-related psychopathology and poor outcomes relative to delinquency, drug and alcohol abuse, and HIV risk behaviors (Steiner, Garcia, & Matthews, 1997). HIV infection is a common public health concern disproportionally affecting adolescent African American female detainees. This unique population has a serious history of violence exposure, which subsequently tends to lead to engaging in risky sexual behaviors, mental health problems, and abusing substances. Also, as a result of little to no intervention, this population is recidivating at an alarming rate, a problem that may further exacerbate the expression of health-related risk behaviors among African American adolescent female detainees. The authors briefly describe a pilot program to be implemented in the juvenile justice system that is based on the Model of Accumulated Risk (Garbarino, 1996), Bronfenbrenner’s Ecological Model (1994), and the Positive Youth Justice Model (Butts, Bazemore, & Meroe, 2009). The program proposes to reduce risky sexual behaviors, teach alternatives to abusing substances, treat mental health concerns, and reduce the rate of recidivism through “positive youth development”, PYD (Butts, Bazemore, & Meroe, 2009). Tying elements of wraparound services and reeducation together, this program addresses salient concerns that may have an impact on an adolescent detainees’ success following their release from prison in a holistic manner. PMID:21373205

  12. Genetic variations in vitamin D-related pathways and breast cancer risk in African American women in the AMBER consortium.

    PubMed

    Yao, Song; Haddad, Stephen A; Hu, Qiang; Liu, Song; Lunetta, Kathryn L; Ruiz-Narvaez, Edward A; Hong, Chi-Chen; Zhu, Qianqian; Sucheston-Campbell, Lara; Cheng, Ting-Yuan David; Bensen, Jeannette T; Johnson, Candace S; Trump, Donald L; Haiman, Christopher A; Olshan, Andrew F; Palmer, Julie R; Ambrosone, Christine B

    2016-05-01

    Studies of genetic variations in vitamin D-related pathways and breast cancer risk have been conducted mostly in populations of European ancestry, and only sparsely in African Americans (AA), who are known for a high prevalence of vitamin D deficiency. We analyzed 24,445 germline variants in 63 genes from vitamin D-related pathways in the African American Breast Cancer Epidemiology and Risk (AMBER) consortium, including 3,663 breast cancer cases and 4,687 controls. Odds ratios (OR) were derived from logistic regression models for overall breast cancer, by estrogen receptor (ER) status (1,983 ER positive and 1,098 ER negative), and for case-only analyses of ER status. None of the three vitamin D-related pathways were associated with breast cancer risk overall or by ER status. Gene-level analyses identified associations with risk for several genes at a nominal p ≤ 0.05, particularly for ER- breast cancer, including rs4647707 in DDB2. In case-only analyses, vitamin D metabolism and signaling pathways were associated with ER- cancer (pathway-level p = 0.02), driven by a single gene CASR (gene-level p = 0.001). The top SNP in CASR was rs112594756 (p = 7 × 10(-5), gene-wide corrected p = 0.01), followed by a second signal from a nearby SNP rs6799828 (p = 1 × 10(-4), corrected p = 0.03). In summary, several variants in vitamin D pathways were associated with breast cancer risk in AA women. In addition, CASR may be related to tumor ER status, supporting a role of vitamin D or calcium in modifying breast cancer phenotypes. PMID:26650177

  13. Genetic variations in vitamin D-related pathways and breast cancer risk in African American women in the AMBER consortium.

    PubMed

    Yao, Song; Haddad, Stephen A; Hu, Qiang; Liu, Song; Lunetta, Kathryn L; Ruiz-Narvaez, Edward A; Hong, Chi-Chen; Zhu, Qianqian; Sucheston-Campbell, Lara; Cheng, Ting-Yuan David; Bensen, Jeannette T; Johnson, Candace S; Trump, Donald L; Haiman, Christopher A; Olshan, Andrew F; Palmer, Julie R; Ambrosone, Christine B

    2016-05-01

    Studies of genetic variations in vitamin D-related pathways and breast cancer risk have been conducted mostly in populations of European ancestry, and only sparsely in African Americans (AA), who are known for a high prevalence of vitamin D deficiency. We analyzed 24,445 germline variants in 63 genes from vitamin D-related pathways in the African American Breast Cancer Epidemiology and Risk (AMBER) consortium, including 3,663 breast cancer cases and 4,687 controls. Odds ratios (OR) were derived from logistic regression models for overall breast cancer, by estrogen receptor (ER) status (1,983 ER positive and 1,098 ER negative), and for case-only analyses of ER status. None of the three vitamin D-related pathways were associated with breast cancer risk overall or by ER status. Gene-level analyses identified associations with risk for several genes at a nominal p ≤ 0.05, particularly for ER- breast cancer, including rs4647707 in DDB2. In case-only analyses, vitamin D metabolism and signaling pathways were associated with ER- cancer (pathway-level p = 0.02), driven by a single gene CASR (gene-level p = 0.001). The top SNP in CASR was rs112594756 (p = 7 × 10(-5), gene-wide corrected p = 0.01), followed by a second signal from a nearby SNP rs6799828 (p = 1 × 10(-4), corrected p = 0.03). In summary, several variants in vitamin D pathways were associated with breast cancer risk in AA women. In addition, CASR may be related to tumor ER status, supporting a role of vitamin D or calcium in modifying breast cancer phenotypes.

  14. Racial and Ethnic-Related Stressors as Predictors of Perceived Stress and Academic Performance for African American Students at a Historically Black College and University

    ERIC Educational Resources Information Center

    Greer, Tawanda M.

    2008-01-01

    The purpose of this investigation was to determine whether racial and ethnic-related stressors were associated with overall levels of perceived stress and academic performance among African American students at a historically Black college and university (HBCU). Hierarchical regression analyses were used to test racial and ethnic-related stressors…

  15. Triglyceride concentration and waist circumference influence alcohol-related plasminogen activator inhibitor-1 activity increase in black South Africans.

    PubMed

    Pieters, Marlien; de Lange, Zelda; Hoekstra, Tiny; Ellis, Suria M; Kruger, Annamarie

    2010-12-01

    We investigated the association between alcohol consumption and plasminogen activator inhibitor-1 activity (PAI-1act) and fibrinogen concentration in a black South African population presenting with lower PAI-1act and higher fibrinogen than what is typically observed in white populations. We, furthermore, wanted to investigate the effect of urbanization, sex, central obesity, increased triglycerides, 4G/5G polymorphism (PAI-1 only) and BMI on the association of alcohol with PAI-1act and fibrinogen. Data from 2010 apparently healthy, randomly collected black South African volunteers from the Prospective Urban and Rural Epidemiological (PURE) study were cross-sectionally analyzed. Alcohol consumption was recorded using quantitative food frequency questionnaires and fasting blood samples were collected for biochemical analysis including PAI-1act and fibrinogen. Heavy alcohol consumption is associated with significantly increased PAI-1act, in the total population as well as in the women separately, and tended to be so in men. This alcohol-related PAI-1act increase was observed in volunteers with increased triglycerides and central obesity but not in volunteers with normal levels and waist circumference. Urbanization, the 4G/5G polymorphism and BMI did not affect the association of alcohol with PAI-1act. Moderate alcohol consumption is associated with decreased fibrinogen concentration. Sex and level of urbanization did not affect the association of alcohol with fibrinogen. Fibrinogen decreased in normal and overweight volunteers but not in obese and centrally obese volunteers following moderate alcohol consumption. Triglyceride levels and waist circumference influence alcohol-related PAI-1act increase potentially through modulating adipocyte and triglyceride-induced PAI-1 production. Obesity prevented alcohol-related fibrinogen decrease possibly by counteracting the anti-inflammatory effect of moderate alcohol consumption.

  16. Routine removal of the plate after surgical treatment for mandibular angle fracture with a third molar in relation to the fracture line

    PubMed Central

    Yamamoto, Kazuhiko; Matsusue, Yumiko; Horita, Satoshi; Murakami, Kazuhiro; Sugiura, Tsutomu; Kirita, Tadaaki

    2015-01-01

    Purpose: The purpose was to analyze the clinical course of surgically treated mandibular angle fractures from the viewpoint of routine removal of the plate because these fractures are associated with high rates of complications and plate removal. Subjects and Methods: The subjects were 40 patients with unilateral mandibular angle fracture, which was intraorally reduced and principally fixed with a single miniplate on the external oblique ridge. The third molar in relation to the fracture line was extracted in seven patients during the surgery. Clinical course was evaluated in terms of removal of the plate, preservation of the third molar and complications. Results: One patient showed a wound infection postoperatively, and two patients developed pericoronitis during the follow-up. These were managed with medication and local irrigation. One patient with a preserved third molar did not make a required visit and was lost from the follow-up. Removal of the plates was performed in 39 patients after confirmation of good fracture healing, mostly within a year. Twenty-four of 32 preserved third molars were simultaneously extracted. These procedures were generally performed under local anesthesia on an outpatient basis, and they did not cause any complications. Conclusions: Routine removal of the plate after surgical treatment for mandibular angle fractures, simultaneously with extraction of the third molar if indicated, may be beneficial to avoid complications related to the plate and the third molar later in life. PMID:26389039

  17. West African monsoon decadal variability and surface-related forcings: second West African Monsoon Modeling and Evaluation Project Experiment (WAMME II)

    NASA Astrophysics Data System (ADS)

    Xue, Yongkang; De Sales, Fernando; Lau, William K.-M.; Boone, Aaron; Kim, Kyu-Myong; Mechoso, Carlos R.; Wang, Guiling; Kucharski, Fred; Schiro, Kathleen; Hosaka, Masahiro; Li, Suosuo; Druyan, Leonard M.; Sanda, Ibrah Seidou; Thiaw, Wassila; Zeng, Ning; Comer, Ruth E.; Lim, Young-Kwon; Mahanama, Sarith; Song, Guoqiong; Gu, Yu; Hagos, Samson M.; Chin, Mian; Schubert, Siegfried; Dirmeyer, Paul; Ruby Leung, L.; Kalnay, Eugenia; Kitoh, Akio; Lu, Cheng-Hsuan; Mahowald, Natalie M.; Zhang, Zhengqiu

    2016-06-01

    The second West African Monsoon Modeling and Evaluation Project Experiment (WAMME II) is designed to improve understanding of the possible roles and feedbacks of sea surface temperature (SST), land use land cover change (LULCC), and aerosols forcings in the Sahel climate system at seasonal to decadal scales. The project's strategy is to apply prescribed observationally based anomaly forcing, i.e., "idealized but realistic" forcing, in simulations by climate models. The goal is to assess these forcings' effects in producing/amplifying seasonal and decadal climate variability in the Sahel between the 1950s and the 1980s, which is selected to characterize the great drought period of the last century. This is the first multi-model experiment specifically designed to simultaneously evaluate such relative contributions. The WAMME II models have consistently demonstrated that SST forcing is a major contributor to the twentieth century Sahel drought. Under the influence of the maximum possible SST forcing, the ensemble mean of WAMME II models can produce up to 60 % of the precipitation difference during the period. The present paper also addresses the role of SSTs in triggering and maintaining the Sahel drought. In this regard, the consensus of WAMME II models is that both Indian and Pacific Ocean SSTs greatly contributed to the drought, with the former producing an anomalous displacement of the Intertropical Convergence Zone before the WAM onset, and the latter mainly contributes to the summer WAM drought. The WAMME II models also show that the impact of LULCC forcing on the Sahel climate system is weaker than that of SST forcing, but still of first order magnitude. According to the results, under LULCC forcing the ensemble mean of WAMME II models can produces about 40 % of the precipitation difference between the 1980s and the 1950s. The role of land surface processes in responding to and amplifying the drought is also identified. The results suggest that catastrophic

  18. The Lower Engadine Window: sediment deposition and accretion in relation to the plate-tectonic evolution of the Eastern Alps

    NASA Astrophysics Data System (ADS)

    Waibel, A. F.; Frisch, W.

    1989-05-01

    The Lower Engadine Window comprises a weakly metamorphosed, heterogeneous mixture of continental fragments and oceanic ophiolites embedded in a disrupted mass of deep-sea sediments ranging from the mid-Jurassic to the Early Eocene, mostly turbidites. Its geological features are reviewed in the light of recent research and its relationships with other Penninic outcrops in the Eastern Alps discussed. In the Falknis, Sulzfluh and Tasna zones it is thought that the entire spectrum of post-Liassic sediments was deposited to the north of the Austro-Alpine continental margin. This is based on downcurrent variations of sedimentary structures to the north or northwest in the same direction as the trend of paleocurrent indicators, and on the close petrographic resemblance of coarse parent rock materials to Austro-Alpine units. Of particular significance are granitic rocks exposed by vertical movements along fault scarps associated with the first formation of oceanic crust. These granitic rocks, together with their Permo-Mesozoic sedimentary cover, were to be eroded and slumped down from the continental margin until the Senonian. Throughout the Jurassic, the clastic sediments were shed laterally onto the abyssal plain and base of the continental slope. Pelagic sedimentation during parts of the Late Jurassic and earliest Cretaceous, including Aptychus limestones deposited close to the calcite compensation depth, suggests that maximum subsidence of the initially passive continental margin had been attained by this time period. With the onset of continental convergence in the earliest Cretaceous, underthrusting of oceanic crust gave rise to an accretionary trench system. The Cretaceous sediments were deposited in a deep-sea fan environment affected by chaotic mass movements from the inner trench wall. It is believed that the close proximity to the source area of the vast majority of Jurassic and Cretaceous deposits reflects the relative motion between the plates, which must have

  19. Movements and corridors of African elephants in relation to protected areas

    NASA Astrophysics Data System (ADS)

    Douglas-Hamilton, I.; Krink, T.; Vollrath, F.

    2005-04-01

    Understanding how mammals satisfy their need for space in fragmenting ecosystems is crucial for ecosystem conservation. Using state-of-the-art global positioning system (GPS) technology we tracked 11 focal African elephants (Loxodonta africana) in Kenya at 3-hourly fix intervals and collected between 34 and 406 days per individual. Our recordings gave a high spatio-temporal resolution compared to previous studies and allowed novel insights into range use. The actual ranges of the tracked elephants are smaller than usually represented. Moreover, the ranges in our sample were complex and not confined to officially designated protected areas, except where fenced. All the unfenced elephants in our sample had distinct `home sectors' linked by `travel' corridors. Within each home sector the elephants concentrated in favourite `core zones'. Such core zones tended to lie in protected areas whereas corridors typically crossed unprotected range. Elephants moved significantly faster along corridors than elsewhere in their range, which suggests awareness of danger outside the protected area. We conclude that understanding the complex use of an animal's range is crucial for conservation planning aiming to balance animal interests with those of human beings that co-habit in their range.

  20. Plant mineral concentrations related to foraging preferences of western lowland gorilla in Central African forest clearings.

    PubMed

    Metsio Sienne, Julia; Buchwald, Rainer; Wittemyer, George

    2014-12-01

    In the Central African rain forest, mineral resources essential to organisms are distributed heterogeneously. Forest clearings, locally known as bais, attract numerous species presumably due to the mineral richness of these sites, though understanding of the factors drawing species to bais remains speculative. Western lowland gorillas (Gorilla g. gorilla) selectively feed on particular plant species and parts within bais, but studies of such feeding preferences have focused on one site. Here, we compared concentrations of minerals and macronutrients from plants gorillas consumed and those they did not in 16 bais to gain inference regarding drivers of resource selection within bais and bai use. The availability of gorilla feeding plants varied between surveyed bais, with some consumed species occurring only at a few bais. Regardless of bai specific species composition, significantly higher concentrations of Na, K, and Ca were found in consumed plants, and other trace minerals were more common in consumed plants. In contrast, macronutrients appeared to play no major role in feeding plant selectivity with consumed species often having lower concentrations than non-consumed species. We found evidence for seasonal differences in Mg and Na concentrations, but the concentrations of other minerals in consumed plants were consistent across time. These findings provide insight to the drivers of bai visitation by gorillas. The high variation in species across bais may elicit use of multiple bais, but the general increased mineral composition of consumed species across bais suggests metabolic requirements may be met through consumption of a variety of species.

  1. Movements and corridors of African elephants in relation to protected areas.

    PubMed

    Douglas-Hamilton, I; Krink, T; Vollrath, F

    2005-04-01

    Understanding how mammals satisfy their need for space in fragmenting ecosystems is crucial for ecosystem conservation. Using state-of-the-art global positioning system (GPS) technology we tracked 11 focal African elephants (Loxodonta africana) in Kenya at 3-hourly fix intervals and collected between 34 and 406 days per individual. Our recordings gave a high spatio-temporal resolution compared to previous studies and allowed novel insights into range use. The actual ranges of the tracked elephants are smaller than usually represented. Moreover, the ranges in our sample were complex and not confined to officially designated protected areas, except where fenced. All the unfenced elephants in our sample had distinct 'home sectors' linked by 'travel' corridors. Within each home sector the elephants concentrated in favourite 'core zones'. Such core zones tended to lie in protected areas whereas corridors typically crossed unprotected range. Elephants moved significantly faster along corridors than elsewhere in their range, which suggests awareness of danger outside the protected area. We conclude that understanding the complex use of an animal's range is crucial for conservation planning aiming to balance animal interests with those of human beings that co-habit in their range.

  2. [Plummer-Vinson syndrome or related syndrome in 3 black African women].

    PubMed

    Aubry, P; Oddes, B; Chazouillères, O; Lebourgeois, M; Delanoue, G; Seurat, P L

    1985-01-01

    The Plummer-Vinson syndrome or "sideropenic dysphagia" is exceptional among Blacks. One case was recently reported in a female patient from Guadeloupe. This study pertains to three cases observed in Senegalese Black women aged 28, 27, and 41 years. These three women were admitted for a dysphagia, in fact in evidence 10, 4, and 7 years respectively before the diagnosis was made. A clinical anemia was noted twice in addition to mucocutaneous disorders (cases 1 and 2). The laboratory tests showed in all three cases a hypochromic microcytic sideropenic anemia (serum iron levels at 32, 14, and 31 mcg 100 ml respectively). Barium swallow films showed esophageal rings in front of C5-C6 (case 1) of T2-T3 (case 2) and a web of fine mucosal folds in front of C5-C6 (case 3). These films were confirmed cineradiographically by esophagoscopy. The treatment consisted of blood transfusions (cases 1 and 2) and administration of iron by injections and or per os. The endoscopic exams were repeated two or three times. Medical treatment rapidly changed the course of disease for the better. No cause for bleeding was found. A chemical achlorhydria (case 1), a provoked hypoachlorhydria (cases 2 and 3) can be retained as associated factors. In light of the frequency of esophageal membranes in the general population and the incidence of sideropenic anemias among African women, the Plummer-Vinson syndrome should be more often detected in Black Africa.

  3. Plant mineral concentrations related to foraging preferences of western lowland gorilla in Central African forest clearings.

    PubMed

    Metsio Sienne, Julia; Buchwald, Rainer; Wittemyer, George

    2014-12-01

    In the Central African rain forest, mineral resources essential to organisms are distributed heterogeneously. Forest clearings, locally known as bais, attract numerous species presumably due to the mineral richness of these sites, though understanding of the factors drawing species to bais remains speculative. Western lowland gorillas (Gorilla g. gorilla) selectively feed on particular plant species and parts within bais, but studies of such feeding preferences have focused on one site. Here, we compared concentrations of minerals and macronutrients from plants gorillas consumed and those they did not in 16 bais to gain inference regarding drivers of resource selection within bais and bai use. The availability of gorilla feeding plants varied between surveyed bais, with some consumed species occurring only at a few bais. Regardless of bai specific species composition, significantly higher concentrations of Na, K, and Ca were found in consumed plants, and other trace minerals were more common in consumed plants. In contrast, macronutrients appeared to play no major role in feeding plant selectivity with consumed species often having lower concentrations than non-consumed species. We found evidence for seasonal differences in Mg and Na concentrations, but the concentrations of other minerals in consumed plants were consistent across time. These findings provide insight to the drivers of bai visitation by gorillas. The high variation in species across bais may elicit use of multiple bais, but the general increased mineral composition of consumed species across bais suggests metabolic requirements may be met through consumption of a variety of species. PMID:24865332

  4. Measuring health-related problem solving among African Americans with multiple chronic conditions: application of Rasch analysis.

    PubMed

    Fitzpatrick, Stephanie L; Hill-Briggs, Felicia

    2015-10-01

    Identification of patients with poor chronic disease self-management skills can facilitate treatment planning, determine effectiveness of interventions, and reduce disease complications. This paper describes the use of a Rasch model, the Rating Scale Model, to examine psychometric properties of the 50-item Health Problem-Solving Scale (HPSS) among 320 African American patients with high risk for cardiovascular disease. Items on the positive/effective HPSS subscales targeted patients at low, moderate, and high levels of positive/effective problem solving, whereas items on the negative/ineffective problem solving subscales mostly targeted those at moderate or high levels of ineffective problem solving. Validity was examined by correlating factor scores on the measure with clinical and behavioral measures. Items on the HPSS show promise in the ability to assess health-related problem solving among high risk patients. However, further revisions of the scale are needed to increase its usability and validity with large, diverse patient populations in the future.

  5. The psychosocial adjustment of African American youth from single mother homes: the relative contribution of parents and peers.

    PubMed

    Chester, Charlene; Jones, Deborah J; Zalot, Alecia; Sterrett, Emma

    2007-01-01

    This study examined the relative roles of parents and peers in the psychosocial adjustment of African American youth (7-15 years old) from single mother homes (N = 242). Main effects of both positive parenting and peer relationship quality were found for youth depressive symptoms. In addition, a main effect of peer relationship quality and an interaction of Positive Parenting x Peer Relationship Quality emerged for youth externalizing symptoms. When mothers engaged in higher levels of positive parenting behavior, peer relationship quality was not associated with youth externalizing symptomatology. When mothers engaged in lower levels of positive parenting behavior, however, higher peer relationship quality was associated with greater youth externalizing symptomatology. Clinical implications and future research directions are discussed.

  6. Subduction Related Crustal and Mantle Deformations and Their Implications for Plate Dynamics

    NASA Astrophysics Data System (ADS)

    Okeler, Ahmet

    Ocean-continent convergence and subsequent continental collision are responsible for continental growth, mountain building, and severe tectonic events including volcanic eruptions and earthquake activity. They are also key driving forces behind the extensive thermal and compositional heterogeneities at crustal and mantle depths. Active subduction along the Calabrian Arc in southern Italy and the Hellenic Arc are examples of such collisional tectonics. The first part of this thesis examines the subduction related deformations within the crust beneath the southern Apennines. By modeling regional surface wave recordings of the largest temporary deployment in the southern Apennines, a lower-crustal/upper-mantle low-velocity volume extending down to 50 km beneath the mountain chain is identified. The magnitude (˜ 0.4 km/s slower) and anisotropic nature (˜ 10%) of the anomaly suggest the presence of hot and partially molten emplacement that may extend into the upper-crust towards Mt. Vulture, a once active volcano. Since the Apulian basement units are deformed during the compressional and consequent extensional events, our observations favor the "thick-skin" tectonic growth model for the region. In the deeper mantle, active processes are thermodynamically imprinted on the depth and strength of the phase transitions. This thesis examines more than 15000 SS precursors and provides the present-day reflectivity structure and topography associated with these phase transitions. Through case studies I present ample evidence for both slab penetration into the lower mantle (beneath the Hellenic Arc, Kurile Island and South America) and slab stagnation at the bottom of the Mantle Transition Zone (beneath the Tyrrhenian Sea and eastern China). Key findings include (1) thermal anomalies (˜ 200 K) at the base of the MTZ, which represent the deep source for Cenozoic European Rift Zone, Mount Etna and Mount Cameroon volcanism, (2) significant depressions (by 20-40 km) at the bottom

  7. Sublatitudinal Isotope Heterogeneity of The Atlantic and Adjacent Continents: A Relation To The Litospheric Plates and Superplums

    NASA Astrophysics Data System (ADS)

    Mironov, Yu. V.; Ryakhovsky, V. M.; Pustovoy, A. A.; Lapidus, I. V.

    Four Sr-Nd-Pb isotope sublatitudinal provinces are chosen in the Atlantic and on ad- jacent continents. They include mid-ocean ridges, oceanic rises and islands, as well as Late Mesozoic - Cenozoic continental rifts and traps. A modified Zindler-Hart "man- tle tetrahedron" (1986) have been used for rock systematics. Its major classification element alongside with known end-members (DM, HIMU, EM1, EM2) is any in- tratetrahedron component F ("focal") (Mironov et al., 2000; Rundquist et al., 2000; Ryakhovsky, 2000). It represents average characteristic of all known intratetrahedron components (FOZO, C, PREMA etc.), updated by methods of multidimensional statis- tics. Northern province includes Mid-Atlantic Ridge from a southern part of Reykjanes ridge up to 24S, numerous islands and rises, located at the same latitudes, Cameroon Line, African and European rifts, Aden and Red sea spreading centres, and also Co- mores in Indian ocean. The main composition dispersion of volcanics from withinplate oceanic and continental structures is determined by mixture of F and HIMU (rarely with admixture EM2). MORB within this area are characterized by stable admixture HIMU. Similar composition have the rocks in Bouvet-Antarctic province, within the limits of which the rises Spiss and Shona, the most southern part of Mid-Atlantic ridge, island Bouvet, an adjacent part of Southwest-Indian Ridge, and also traps and rifts on northern coast of Antarctic Continent are located. The Southern province lies in outlines of known Southern hemisphere DUPAL-anomaly (Hart, 1984). The with- inplate oceanic rocks (Gough, Tristan-da-Kunha, Walvis ridge, Rio Grande Plateau, Discovery) correspond to a mixture F + EM1 (sometimes F + EM1 + EM2) and are similar with traps of Southern America and Africa. Further to east this province is traced on islands and mid-ocean ridges in Indian ocean. MORB of Southern Atlantic and Indian ocean are enriched EM1. The Arctic province includes spreading ridges of

  8. The association between disaster-related experiences and mental health outcomes among drug using African American Hurricane Katrina evacuees.

    PubMed

    Cepeda, Alice; Saint Onge, Jarron M; Kaplan, Charles; Valdez, Avelardo

    2010-12-01

    This article provides a detailed examination of the relationship between disaster-related experiences and mental health outcomes among a sample of drug using African American Hurricane Katrina evacuees. Face-to-face structured interviews were administered to Hurricane Katrina evacuees (n = 350) residing in voucher assisted apartment complexes in Houston, Texas (2006-2007). We use Ordinary Least Squares and logistic regression models to examine both the relevance of disaster-related experiences and the interactive relationships between disaster-related experiences and post-disaster mental health outcomes including psychological distress, severe depression, somatic symptoms, and posttraumatic stress disorder. Results indicate that disaster-related experiences including negative life changes, disaster exposure, post-disaster stressors, and resource loss, have unique, inverse relationships with mental health. While resource loss has the strongest inverse relationship with mental health, disaster exposure has a negative interactive effect on psychological distress and anxiety. Although highly vulnerable populations report low levels of mental health nearly 2 years following a disaster experience, there is a convergence in mental health outcomes with high levels of disaster experiences and disaster exposure that suggests mental resiliency.

  9. Seismic structure related to the Philippine Sea plate subduction beneath the southwestern Nansei-Shoto (Ryukyu) Trench

    NASA Astrophysics Data System (ADS)

    Nishizawa, A.; Kaneda, K.; Oikawa, M.; Horiuchi, D.; Fujioka, Y.

    2013-12-01

    The northwestern part of the Philippine Sea plate (PSP) is subducting beneath the Nansei-Shoto (Ryukyu) Trench. Earthquakes larger than M8 have not been recorded instrumentally in the southwestern part of the Ryukyu Trench. However, there was a large tsunami killed around 12,000 people in 1771 and the position of the source area has not been established. The direction of the PSP subduction is almost perpendicular to the Ryukyu Trench to the northeast of 126.5 E and changes to oblique to the southwest. Seismicity varies along the trench axis and lower seismicity seems to correspond to the free-air gravity anomaly high region in the forearc at around 126 E. On the other hand, the Okinawa-Luzon fracture zone extending from southwest to northeast on the PSP subducts beneath Ryukyu Trench to the northeast of 126 E and seems to relate to the high gravity anomaly. We carried out seismic experiments to elucidate these inhomogeneous crustal structures along the southwestern part of the trench and provide valuable information on potential source areas for large earthquakes and/or tsunamis. We conducted five seismic lines across southwestern Ryukyu Trench region. Multichannel reflection seismic (MCS) data using 240 ch. and 3000 m long hydrophone streamer were collected for airgun shots at an interval of 50 m. We also deployed ocean bottom seismographs (OBSs) as a receiver at an average interval of 5 km along each line. A tri-gun cluster with a volume of 1,050 (350 * 3) cubic inches (17.2 liters) was used for the reflection surveys and a non-tuned airgun array with a volume of 6,000 (1500 * 4) cubic inches (98 liters) was shot at an interval of 200 m (90 sec) for the wide-angle seismic survey. Depth conversion from the MCS time section was carried out using the refraction results. In this paper, we present the seismic structure related to the PSP subduction in the forearc region of the Nansei-Shoto island arc. The subducting Okinawa-Luzon fracture zone was able to be clearly

  10. Is there a legacy of the U.S. Public Health Syphilis Study at Tuskegee in HIV/AIDS-related beliefs among heterosexual African-Americans and Latinos?

    PubMed

    Mays, Vickie M; Coles, Courtney N; Cochran, Susan D

    2012-01-01

    Knowledge of the US Public Health Syphilis Study at Tuskegee is sometime cited as a principal reason for the relatively low participation rates seen among racial/ethnic minorities, particularly African Americans, in biomedical research. However, only a few studies have actually explored this possibility. We use data from a random digit dial telephone survey of 510 African-Americans and 253 Latinos, age 18 to 45 years, to investigate associations between knowledge of the USPHS Syphilis Study at Tuskegee and endorsement of HIV/AIDS conspiracy theories. All respondents were drawn from an area of low-income, predominantly race-segregated inner city households in Los Angeles. Results indicate that African Americans were significantly more likely than Latinos to endorse HIV/AIDS conspiracy theories. Further, African Americans were more aware of the USPHS Syphilis Study at Tuskegee (SST). Nevertheless, 72% of African Americans and 94% of Latinos reported that they have never heard of the Syphilis Study at Tuskegee. Further, while awareness of the Syphilis Study at Tuskegee was a significant predictor of endorsing HIV/AIDS conspiracy theories, results suggest that other factors may be more important in accounting for low biomedical and behavioral study participation rates. PMID:23308036

  11. Saying Grace: Praying over the Loss of African-American Religious and Food Culture (and How They Are Related)

    ERIC Educational Resources Information Center

    Hinton, Mary

    2008-01-01

    This article investigates the joint losses of food and religious culture in the African-American community, which has had a significant impact on the African-American community. Beginning with a historical perspective on the role of food in both a religious and cultural context, the article offers an analysis of why the dual losses have occurred,…

  12. Explaining disproportionately high rates of adverse birth outcomes among African Americans: the impact of stress, racism, and related factors in pregnancy.

    PubMed

    Giscombé, Cheryl L; Lobel, Marci

    2005-09-01

    Compared with European Americans, African American infants experience disproportionately high rates of low birth weight and preterm delivery and are more than twice as likely to die during their 1st year of life. The authors examine 5 explanations for these differences in rates of adverse birth outcomes: (a) ethnic differences in health behaviors and socioeconomic status; (b) higher levels of stress in African American women; (c) greater susceptibility to stress in African Americans; (d) the impact of racism acting either as a contributor to stress or as a factor that exacerbates stress effects; and (e) ethnic differences in stress-related neuroendocrine, vascular, and immunological processes. The review of literature indicates that each explanation has some merit, although none is sufficient to explain ethnic disparities in adverse birth outcomes. There is a lack of studies examining the impact of such factors jointly and interactively. Recommendations and cautions for future research are offered.

  13. European American and African American Mothers’ Emotion Socialization Practices Relate Differently to their Children’s Academic and Social-Emotional Competence

    PubMed Central

    Nelson, Jackie A.; Leerkes, Esther M.; Perry, Nicole B.; O’Brien, Marion; Calkins, Susan D.; Marcovitch, Stuart

    2012-01-01

    The current study examines whether the relation between mothers’ responses to their children’s negative emotions and teachers’ reports of children’s academic performance and social-emotional competence are similar or different for European American and African American families. Two hundred mothers (137 European American, 63 African American) reported on their responses to their 5-year-old children’s negative emotions and 150 kindergarten teachers reported on these children’s current academic standing and skillfulness with peers. Problem-focused responses to children’s negative emotions, which have traditionally been considered a supportive response, were positively associated with children’s school competence for European American children, but expressive encouragement, another response considered supportive, was negatively associated with children’s competence for African American children. The findings highlight the need to examine parental socialization practices from a culturally-specific lens. PMID:23914076

  14. Lack of Co-occurring Interpersonal Violence Emotionally-Related Difficulties, or Alcohol and Other-Drug Problems among African American Youth with Conduct Disorder.

    ERIC Educational Resources Information Center

    Singleton, Edward G.; Dale, Grady A., Jr.

    Case studies of African American youth with conduct disorder were examined in the context of a descriptive evaluation of co-occurring substance-related problems and mental disorders. The purpose of this study was to extend the findings of the Epidemiologic Catchment Area (ECA) study of the National Institute of Mental Health into the area of…

  15. U.S. Church-Related Funding for Change in South Africa: An Analysis and an Inventory. South African Information Exchange Working Paper Number 7.

    ERIC Educational Resources Information Center

    Micou, Ann McKinstry

    A working paper on U.S. church-related funding for (or sponsorship of) South African programs is presented to guide support-seeking organizations in South Africa to appropriate resources and to inform interested parties outside South Africa about potential resources and ways in which they might cooperate or assist. Information is provided in two…

  16. School Characteristics and Experiences of African American, Hispanic/Latino, and Native American Youth in Rural Communities: Relation to Educational Aspirations

    ERIC Educational Resources Information Center

    Irvin, Matthew J.; Byun, Soo-yong; Meece, Judith L.; Reed, Karla S.; Farmer, Thomas W.

    2016-01-01

    The primary purpose of this study was to examine differences in the school characteristics and experiences of African American, Hispanic/Latino, and Native American youth in rural high schools as well as their relation to educational aspirations. We also investigated the characteristics and experiences of students and their families given that…

  17. European-American and African-American Mothers' Emotion Socialization Practices Relate Differently to Their Children's Academic and Social-Emotional Competence

    ERIC Educational Resources Information Center

    Nelson, Jackie A.; Leerkes, Esther M.; Perry, Nicole B.; O'Brien, Marion; Calkins, Susan D.; Marcovitch, Stuart

    2013-01-01

    The current study examines whether the relation between mothers' responses to their children's negative emotions and teachers' reports of children's academic performance and social-emotional competence are similar or different for European-American and African-American families. Two hundred mothers (137 European-American, 63…

  18. Measurement characteristics of activity-related psychosocial measures in 8- to 10-year-old African-American girls in the Girls health Enrichment Multisite Study (GEMS)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    BACKGROUND: This paper presents reliability and validity analyses of physical activity-related psychosocial questionnaires completed by 8- to 10-year-old African-American girls at baseline and follow-up assessments of pilot intervention studies in the Girls health Enrichment Multi-site Study (GEMS)....

  19. Cultural, Sociofamilial, and Psychological Resources that Inhibit Psychological Distress in African Americans Exposed to Stressful Life Events and Race-Related Stress

    ERIC Educational Resources Information Center

    Utsey, Shawn O.; Giesbrecht, Norman; Hook, Joshua; Stanard, Pia M.

    2008-01-01

    This study tested a sociocultural model of stress and coping in a sample of 215 African Americans. Psychological resources (optimism, ego resilience) were modeled as a "nested self" (S. E. Hobfoll, 2001), supported by social resources (family adaptability and cohesion) and cultural resources (racial pride, religiosity). Race-related stress was a…

  20. Examining the Relational Processes of a Highly Successful Teacher of African American Children

    ERIC Educational Resources Information Center

    Cholewa, Blaire; Amatea, Ellen; West-Olatunji, Cirecie A.; Wright, Ashley

    2012-01-01

    Culturally responsive educational practices have arisen as effective means of increasing culturally diverse students' academic achievement and psychological well-being; however, the relational processes involved are not well understood. Using grounded theory, this study examines the relational processes of one culturally responsive teacher and her…

  1. Nodal Constraint, Shear Deformation and Continuity Effects Related to the Modeling of Debonding of Laminates, Using Plate Elements

    NASA Technical Reports Server (NTRS)

    Glaessgen, E. H.; Riddell, W. T.; Raju, I. S.

    2002-01-01

    The effects of several critical assumptions and parameters on the computation of strain energy release rates for delamination and debond configurations modeled with plate elements have been quantified. The method of calculation is based on the virtual crack closure technique (VCCT), and models of the upper and lower surface of the delamination or debond that use two-dimensional (2D) plate elements rather than three-dimensional (3D) solid elements. The major advantages of the plate element modeling technique are a smaller model size and simpler configurational modeling. Specific issues that are discussed include: constraint of translational degrees of freedom, rotational degrees of freedom or both in the neighborhood of the debond front, shear deformation assumptions; and continuity of material properties and section stiffness in the vicinity of the debond front. Where appropriate, the plate element analyses are compared with corresponding two-dimensional plane strain analyses.

  2. Geologically current plate motions

    NASA Astrophysics Data System (ADS)

    DeMets, Charles; Gordon, Richard G.; Argus, Donald F.

    2010-04-01

    We describe best-fitting angular velocities and MORVEL, a new closure-enforced set of angular velocities for the geologically current motions of 25 tectonic plates that collectively occupy 97 per cent of Earth's surface. Seafloor spreading rates and fault azimuths are used to determine the motions of 19 plates bordered by mid-ocean ridges, including all the major plates. Six smaller plates with little or no connection to the mid-ocean ridges are linked to MORVEL with GPS station velocities and azimuthal data. By design, almost no kinematic information is exchanged between the geologically determined and geodetically constrained subsets of the global circuit-MORVEL thus averages motion over geological intervals for all the major plates. Plate geometry changes relative to NUVEL-1A include the incorporation of Nubia, Lwandle and Somalia plates for the former Africa plate, Capricorn, Australia and Macquarie plates for the former Australia plate, and Sur and South America plates for the former South America plate. MORVEL also includes Amur, Philippine Sea, Sundaland and Yangtze plates, making it more useful than NUVEL-1A for studies of deformation in Asia and the western Pacific. Seafloor spreading rates are estimated over the past 0.78 Myr for intermediate and fast spreading centres and since 3.16 Ma for slow and ultraslow spreading centres. Rates are adjusted downward by 0.6-2.6mmyr-1 to compensate for the several kilometre width of magnetic reversal zones. Nearly all the NUVEL-1A angular velocities differ significantly from the MORVEL angular velocities. The many new data, revised plate geometries, and correction for outward displacement thus significantly modify our knowledge of geologically current plate motions. MORVEL indicates significantly slower 0.78-Myr-average motion across the Nazca-Antarctic and Nazca-Pacific boundaries than does NUVEL-1A, consistent with a progressive slowdown in the eastward component of Nazca plate motion since 3.16 Ma. It also

  3. A Qualitative Study for Understanding Family and Peer Influences on Obesity-Related Health Behaviors in Low-Income African-American Adolescents

    PubMed Central

    Wilson, Dawn K.

    2012-01-01

    Background Given the cultural and developmental relevance of family members and peers in the lives of African-American adolescents, the present study used a bioecological framework to qualitatively explore the parenting context as well as specific family factors (support, rules, monitoring) and peer factors (support) related to weight status, physical activity (PA), and healthy eating in low-income African-American boys versus girls. Methods Qualitative data were obtained from African-American adolescents through focus groups. Adolescents (n=45, 100% African American, 51% girls, 12.6±1.2 years, 51% overweight/obese) were from two underserved communities in South Carolina (median income ≈$17,000–$22,000, high crime levels). Sessions were audiotaped, transcribed, and coded by independent pairs of raters (r=0.75). QSR NVivo 8 was used to analyze data, and themes were categorized separately for boys and girls. Results Adolescents reported themes of family warmth and control practices consistent with an authoritative style of parenting. Although adolescents wanted increased autonomy, they viewed parental monitoring as a favorable part of their relationship. Boys reported receiving more constructive feedback from parents about weight status and greater overall support for PA and diet than did girls. Girls reported more honest feedback from peers about weight status than did boys. Overall, adolescents acknowledged the unique opportunities of parents and peers in improving their health behaviors. Conclusions Findings suggest parents and peers interact in different ways with African-American boys and girls regarding their weight status and health behaviors. Future obesity prevention efforts in minority youth may need to target parenting skills that provide greater support to African-American girls. In addition, given peers influence PA and diet differently in boys and girls, interventions should strategically include parenting strategies that involve monitoring peer

  4. Tree foliar chemistry in an African savanna and its relation to life history strategies and environmental filters.

    PubMed

    Colgan, Matthew S; Martin, Roberta E; Baldeck, Claire A; Asner, Gregory P

    2015-01-01

    Understanding the relative importance of environment and life history strategies in determining leaf chemical traits remains a key objective of plant ecology. We assessed 20 foliar chemical properties among 12 African savanna woody plant species and their relation to environmental variables (hillslope position, precipitation, geology) and two functional traits (thorn type and seed dispersal mechanism). We found that combinations of six leaf chemical traits (lignin, hemi-cellulose, zinc, boron, magnesium, and manganese) predicted the species with 91% accuracy. Hillslope position, precipitation, and geology accounted for only 12% of the total variance in these six chemical traits. However, thorn type and seed dispersal mechanism accounted for 46% of variance in these chemical traits. The physically defended species had the highest concentrations of hemi-cellulose and boron. Species without physical defense had the highest lignin content if dispersed by vertebrates, but threefold lower lignin content if dispersed by wind. One of the most abundant woody species in southern Africa, Colophospermum mopane, was found to have the highest foliar concentrations of zinc, phosphorus, and δ(13)C, suggesting that zinc chelation may be used by this species to bind metallic toxins and increase uptake of soil phosphorus. Across all studied species, taxonomy and physical traits accounted for the majority of variability in leaf chemistry. PMID:25993539

  5. Tree foliar chemistry in an African savanna and its relation to life history strategies and environmental filters.

    PubMed

    Colgan, Matthew S; Martin, Roberta E; Baldeck, Claire A; Asner, Gregory P

    2015-01-01

    Understanding the relative importance of environment and life history strategies in determining leaf chemical traits remains a key objective of plant ecology. We assessed 20 foliar chemical properties among 12 African savanna woody plant species and their relation to environmental variables (hillslope position, precipitation, geology) and two functional traits (thorn type and seed dispersal mechanism). We found that combinations of six leaf chemical traits (lignin, hemi-cellulose, zinc, boron, magnesium, and manganese) predicted the species with 91% accuracy. Hillslope position, precipitation, and geology accounted for only 12% of the total variance in these six chemical traits. However, thorn type and seed dispersal mechanism accounted for 46% of variance in these chemical traits. The physically defended species had the highest concentrations of hemi-cellulose and boron. Species without physical defense had the highest lignin content if dispersed by vertebrates, but threefold lower lignin content if dispersed by wind. One of the most abundant woody species in southern Africa, Colophospermum mopane, was found to have the highest foliar concentrations of zinc, phosphorus, and δ(13)C, suggesting that zinc chelation may be used by this species to bind metallic toxins and increase uptake of soil phosphorus. Across all studied species, taxonomy and physical traits accounted for the majority of variability in leaf chemistry.

  6. Tree Foliar Chemistry in an African Savanna and Its Relation to Life History Strategies and Environmental Filters

    PubMed Central

    Colgan, Matthew S.; Martin, Roberta E.; Baldeck, Claire A.; Asner, Gregory P.

    2015-01-01

    Understanding the relative importance of environment and life history strategies in determining leaf chemical traits remains a key objective of plant ecology. We assessed 20 foliar chemical properties among 12 African savanna woody plant species and their relation to environmental variables (hillslope position, precipitation, geology) and two functional traits (thorn type and seed dispersal mechanism). We found that combinations of six leaf chemical traits (lignin, hemi-cellulose, zinc, boron, magnesium, and manganese) predicted the species with 91% accuracy. Hillslope position, precipitation, and geology accounted for only 12% of the total variance in these six chemical traits. However, thorn type and seed dispersal mechanism accounted for 46% of variance in these chemical traits. The physically defended species had the highest concentrations of hemi-cellulose and boron. Species without physical defense had the highest lignin content if dispersed by vertebrates, but threefold lower lignin content if dispersed by wind. One of the most abundant woody species in southern Africa, Colophospermum mopane, was found to have the highest foliar concentrations of zinc, phosphorus, and δ13C, suggesting that zinc chelation may be used by this species to bind metallic toxins and increase uptake of soil phosphorus. Across all studied species, taxonomy and physical traits accounted for the majority of variability in leaf chemistry. PMID:25993539

  7. Cervical Neoplasia-Related Factors and Decreased Prevalence of Uterine Fibroids among a Cohort of African-American Women

    PubMed Central

    Moore, Kristen R.; Smith, Jennifer S.; Laughlin-Tommaso, Shannon K.; Baird, Donna D.

    2013-01-01

    Objective To investigate whether the previously reported inverse association between cervical neoplasia and uterine fibroids is corroborated. Design Cross-sectional analysis of enrollment data from an ongoing prospective study of fibroid development. Setting Detroit, Michigan area. Patients(s) Self-reported data on abnormal Pap smear, colposcopy and cervical treatment were obtained from 1,008 African-American women ages 23-34 with no previous fibroid diagnosis and no reported history of HPV vaccination. Presence of fibroids was assessed at a standardized ultrasound examination. Intervention(s) None. Main Outcome Measure(s) The association between the 3 cervical neoplasia-related variables and presence of fibroids was evaluated with logistic regression to estimate age-adjusted and multivariable-adjusted odds ratios (ORs). Result(s) Of the analysis sample, 46%, 29% and 14% reported a prior abnormal Pap smear, colposcopy and cervical treatment, respectively. Twenty-five percent had fibroids at ultrasound. Those reporting cervical treatment had a 39% [aOR: 0.61, 95%CI (0.38-0.96)] reduction in fibroid risk. Weak non-significant associations were found for abnormal Pap smear and colposcopy. Conclusion(s) Although a protective-type association of cervical neoplasia with uterine fibroids seems counter intuitive, a causal pathway is possible, and the findings are consistent with two prior studies. Further investigation is needed on the relationship between fibroids and cervical neoplasia and HPV-related mechanisms. PMID:24268705

  8. Sonication for diagnosis of catheter-related infection is not better than traditional roll-plate culture: a prospective cohort study with 975 central venous catheters.

    PubMed

    Erb, Stefan; Frei, Reno; Schregenberger, Katharina; Dangel, Marc; Nogarth, Danica; Widmer, Andreas F

    2014-08-15

    This prospective randomized controlled study with 975 nontunneled central venous catheters (CVCs) showed that the semiquantitative roll-plate culture technique (SQC) was as accurate as the sonication method for diagnosis of catheter-related infections. Sonication is difficult to standardize, whereas SQC is simpler, faster, and as reliable as the sonication method for culturing CVCs.

  9. Multi-decadal carbon and water relations of African tropical humid forests: a tree-ring stable isotope analysis

    NASA Astrophysics Data System (ADS)

    Hufkens, K.; Beeckman, H.; de Haulleville, T.; Kearsley, E.; Toirambe, B.; Stoffelen, P.; Boeckx, P. F.

    2012-12-01

    Little is known about the temporal dynamics of the carbon sequestering capacity and dynamics of African tropical humid forest ecosystems in response to various environmental drivers. This lack of knowledge is mainly due to the absence of ecosystem scale flux measurements of gas exchange. However, tree growth often displays itself as alternating pattern of visible rings due to the varying growth speed of the vascular cambium. Consequently, analysis of tree growth through tree-ring analysis provides us with insights into past responses of the carbon sequestering capacity of key species to abrupt ecosystem disturbances and, while slower, a changing climate. Not only does the width and density of growth rings reflect annual growth but their isotopic composition of 13C and 18O isotopes also reveal the environmental conditions in which the trees were growing. In particular, stable isotope ratios in tree-rings of 13C are influenced by fractionation through carboxylation and changes in stomatal conductance. Similarly, fractionation of 18O from soil water occurs at the leaf level through evapo-transipiration. As a consequence, δ18O values in tree cores will reflect both the signal of the source water as well as that of for example summer humidity. Therefore, using both 13C and 18O stable isotopes might not only be valuable proxies of past climatic conditions but also serve as an important tool in understanding carbon and water relations within a forest ecosystems. To this end we correlate long term climate records (1961 - present) with tree ring measurement of incremental growth and high resolution analysis of tree-core stable isotope (13C / 18O) composition at two functionally similar, but geographically dissimilar, tropical humid forests in DR Congo. A first site, the Luki man and the biosphere (MAB) reserve, is located in the western part of DR Congo influenced by a tropical wet and dry climate. A second site, the Yangambi MAB reserve is located in the north

  10. Multi-decadal carbon and water relations of African tropical humid forests: a tree-ring stable isotope analysis

    NASA Astrophysics Data System (ADS)

    Hufkens, Koen; Helle, Gerd; Beeckman, Hans; de Haulleville, Thales; Kearsley, Elizabeth; Boeckx, Pascal

    2013-04-01

    Little is known about the temporal dynamics of the carbon sequestering capacity and dynamics of African tropical humid forest ecosystems in response to various environmental drivers. This lack of knowledge is mainly due to the absence of ecosystem scale flux measurements of gas exchange. However, tree growth often displays itself as alternating pattern of visible rings due to the seasonally varying growth speed of the vascular cambium. Consequently, analysis of tree growth through tree-ring analysis provides us with insights into past responses of the carbon sequestering capacity of key species to abrupt ecosystem disturbances and, while slower, a changing climate. Not only does the width and density of growth rings reflect annual growth but their isotopic composition of 13C/12C and 18O/16O isotopes also reveal the environmental conditions in which the trees were growing. In particular, stable isotope ratios in tree-rings of carbon are influenced by fractionation through carboxylation during photosynthesis and changes in leaf stomatal conductance. Similarly, fractionation of oxygen isotopes of soil water occurs at the leaf level through evapo-transipiration. As a consequence, 18O/16O (δ18O) values in wood cores will reflect both the signal of the source water as well as that of for example summer humidity. Therefore, both C and O stable isotopes might not only be valuable as proxy data for past climatic conditions but they also serve as an important tool in understanding carbon and water relations within a tropical forest ecosystems. To this end we correlate long term climate records (1961 - present) with tree ring measurement of incremental growth and high resolution analysis of tree-core stable isotope composition(δ13C , δ18O) at a tropical humid forests in the DR Congo. The Yangambi Man And Biosphere (MAB) reserve is located in the north-eastern part of DR Congo, with a distinct tropical rainforest climate. In addition to the tree-core data records and

  11. Distribution and migration of aftershocks of the 2010 Mw 7.4 Ogasawara Islands intraplate normal-faulting earthquake related to a fracture zone in the Pacific plate

    NASA Astrophysics Data System (ADS)

    Obana, Koichiro; Takahashi, Tsutomu; No, Tetsuo; Kaiho, Yuka; Kodaira, Shuichi; Yamashita, Mikiya; Sato, Takeshi; Nakamura, Takeshi

    2014-04-01

    describe the aftershocks of a Mw 7.4 intraplate normal-faulting earthquake that occurred 150 km east Ogasawara (Bonin) Islands, Japan, on 21 December 2010. It occurred beneath the outer trench slope of the Izu-Ogasawara trench, where the Pacific plate subducts beneath the Philippine Sea plate. Aftershock observations using ocean bottom seismographs (OBSs) began soon after the earthquake and multichannel seismic reflection surveys were conducted across the aftershock area. Aftershocks were distributed in a NW-SE belt 140 km long, oblique to the N-S trench axis. They formed three subparallel lineations along a fracture zone in the Pacific plate. The OBS observations combined with data from stations on Chichi-jima and Haha-jima Islands revealed a migration of the aftershock activity. The first hour, which likely outlines the main shock rupture, was limited to an 80 km long area in the central part of the subsequent aftershock area. The first hour activity occurred mainly around, and appears to have been influenced by, nearby large seamounts and oceanic plateau, such as the Ogasawara Plateau and the Uyeda Ridge. Over the following days, the aftershocks expanded beyond or into these seamounts and plateau. The aftershock distribution and migration suggest that crustal heterogeneities related to a fracture zone and large seamounts and oceanic plateau in the incoming Pacific plate affected the rupture of the main shock. Such preexisting structures may influence intraplate normal-faulting earthquakes in other regions of plate flexure prior to subduction.

  12. Lung cancer risk in relation to genetic polymorphisms of microsomal epoxide hydrolase among African-Americans and Caucasians in Los Angeles County.

    PubMed

    London, S J; Smart, J; Daly, A K

    2000-05-01

    Microsomal epoxide hydrolase participates in the metabolism of benzo[a]pyrene, an important carcinogen in tobacco smoke. Two relatively common polymorphisms of the microsomal epoxide hydrolase gene that influence enzyme activity have been described. An association between genetic variation in microsomal epoxide hydrolase and lung cancer risk has been reported in one of two studies of Caucasians. We examined the relation between these two polymorphisms and lung cancer risk among 337 incident cases and 700 population controls of African-American and Caucasian ethnicity enrolled in a case-control study in Los Angeles County. African-Americans, homozygous for the exon 3 variant allele conferring reduced activity, were at decreased risk of lung cancer (odds ratio (OR)=0.08, 95% CI 0.01-0.62). When data from both the exon 3 and exon 4 polymorphisms were combined into indices of predicted microsomal epoxide hydrolase activity, a decreased risk was seen among African-American subjects with very low predicted activity OR=0.10 (95% CI 0.01-0.83). No comparable association was seen among Caucasians. Although the three published results for Caucasians are somewhat variable, the association among African-Americans in these data provides some support for the hypothesis that genetically reduced microsomal epoxide hydrolase activity may be protective against lung cancer.

  13. Relative risk of Alzheimer disease and age-at-onset distributions, based on APOE genotypes among elderly African Americans, Caucasians, and Hispanics in New York City.

    PubMed Central

    Tang, M. X.; Maestre, G.; Tsai, W. Y.; Liu, X. H.; Feng, L.; Chung, W. Y.; Chun, M.; Schofield, P.; Stern, Y.; Tycko, B.; Mayeux, R.

    1996-01-01

    Apolipoprotein-E epsilon 4 (APOE-epsilon 4) has been consistently associated with Alzheimer disease (AD) and may be responsible for an earlier age at onset. We have previously reported a diminished association between APOE-epsilon 4 and AD in African Americans. Using a new method, which allows inclusion of censored information, we compared relative risks by APOE genotypes in an expanded collection of cases and controls from three ethnic groups in a New York community. The relative risk for AD associated with APOE-epsilon 4 homozygosity was increased in all ethnic groups (African American relative risk [RR]=3.0; 95% confidence interval [CI]=1.5-5.9; Caucasian RR=7.3, 95% CI=2.5-21.6; and Hispanic RR=2.5, 95% CI=1.1-5.7), compared with those with APOE-epsilon 3/epsilon 3 genotypes. The risk was also increased for APOE-epsilon 4 heterozygous Caucasians (RR=2.9, 95% CI=1.7-5.1) and Hispanics (RR=1.6, 95% CI=1.1-2.3), but not for African Americans (RR=0.6, 95% Ci=0.4-0.9). The age distribution of the proportion of Caucasians and Hispanics without AD was consistently lower for APOE-epsilon 4 homozygous and APOE-epsilon 4 heterozygous individuals than for those with other APOE genotypes. In African Americans this relationship was observed only in APOE-epsilon 4 homozygotes. These results confirm that APOE genotypes influence the RR of AD in Caucasians and Hispanics. Differences in risk among APOE-epsilon 4 heterozygote African Americans suggest that other genetic or environmental factors may modify the effect of APOE-epsilon 4 in some populations. PMID:8644717

  14. Relative risk of Alzheimer disease and age-at-onset distributions, based on APOE genotypes among elderly African Americans, caucasians, and hispanics in New York City

    SciTech Connect

    Tang, M.X.; Liu, X.H.; Stern, Y.

    1996-03-01

    Apolipoprotein-E {epsilon}4 (APOE-{epsilon}4) has been consistently associated with Alzheimer disease (AD) and may be responsible for an earlier age at onset. We have previously reported a diminished association between APOE-{epsilon}4 and AD in African Americans. Using a new method, which allows inclusion of censored information, we compared relative risks by APOE genotypes in an expanded collection of cases and controls from three ethnic groups in a New York community. The relative risk for AD associated with APOE-{epsilon}4 homozygosity was increased in all ethnic groups (African American relative risk [RR] = 3.0; 95% confidence interval [CI] = 1.5-5.9; Caucasian RR = 7.3, 95% CI = 2.5-21.6; and Hispanic RR = 2.5, 95% CI = 1.1-5.7), compared with those with APOE-{epsilon}3/{epsilon}3 genotypes. The risk was also increased for APOE-{epsilon}4 heterozygous Caucasians (RR = 2.9, 95% CI = 1.7-5.1) and Hispanics (RR = 1.6,95% CI = 1.1-2.3), but not for African Americans (RR = 0.6, 95% CI = 0.4-0.9). The age distribution of the proportion of Caucasians and Hispanics without AD was consistently lower for APOE-{epsilon}4 homozygous and APOE-{epsilon}4 heterozygous individuals than for those with other APOE genotypes. In African Americans this relationship was observed only in APOE-{epsilon}4 homozygotes. These results confirm that APOE genotypes influence the RR of AD in Caucasians and Hispanics. Differences in risk among APOE-{epsilon}4 heterozygote African Americans suggest that other genetic or environmental factors may modify the effect of APOE-{epsilon}4 in some populations. 58 refs., 3 figs., 4 tabs.

  15. Knowledge, Beliefs, and Behaviors: Examining Human Papillomavirus-Related Gender Differences among African American College Students

    ERIC Educational Resources Information Center

    Bynum, Shalanda A.; Brandt, Heather M.; Friedman, Daniela B.; Annang, Lucy; Tanner, Andrea

    2011-01-01

    Objective: Given recent approval for administration of a human papillomavirus (HPV) vaccine to men, it is important to assess the HPV-related perspectives of men and women. The purpose of this study was to examine gender differences in HPV knowledge, beliefs, and vaccine acceptance among college students attending 3 historically black…

  16. Parent & Family Influences on Adopting Healthy Weight-Related Behaviors: Views and Perceptions of Obese African-American Female Adolescents.

    PubMed

    Pratt, Keeley J; McRitchie, Susan; Collier, David N; Lutes, Lesley D; Sumner, Susan

    2015-06-01

    RTI International is acknowledged for supporting the time of Susan McRitchie, Keeley Pratt and Susan Sumner to participate in the design, execution, or analysis of this study. East Carolina University would like to acknowledge Brittney France for being a triangulated investigator for the qualitative analysis and to the Pitt Memorial Hospital Foundation for financial support of the healthy lifestyles camp. Our purpose was to evaluate the views of obese African-American (AA) female adolescents concerning parent and family factors relating to obesity and a healthy lifestyle. Obese AA female adolescents enrolled in a residential healthy lifestyle program completed inventories measuring family functioning and perceptions of parenting styles, and participated in focus groups to identify themes regarding parent and family involvement in healthy lifestyle change. The majority of participants' mothers were scored as "inductive/authoritative" and fathers were "indulgent". Mothers reportedly were seen as more likely to encourage dieting to control weight than fathers. Common themes of the focus groups included a desire for family involvement, identification of family behaviors that were supportive as well as those which were perceived as unhelpful. Though generalizability of these results is limited by a homogenous small sample size, our results suggest that obese adolescents seeking weight loss treatment desire significant family involvement in their efforts. PMID:27269493

  17. Paraffin-related injury in low-income South African communities: knowledge, practice and perceived risk

    PubMed Central

    Swart, Dehran; Hui, Siu-kuen Azor; Simpson, Jennifer; Hobe, Phumla

    2009-01-01

    Abstract Objective To explore what individuals at risk of injury from using paraffin (also known as kerosene) know about paraffin safety, what they do to protect themselves and their families from paraffin-related injury, and how they perceive their risk for such injury. Also, to explore interrelations between these factors and age, sex, education and income. Methods A sample of 238 individuals was randomly recruited from low-income housing districts near Cape Town, South Africa in 2007. Trained research assistants interviewed participants to explore their knowledge about paraffin-related safety and their perceived risk of injury from using paraffin. Researchers inspected participants’ homes to evaluate paraffin safety practices. Descriptive and correlational analyses were conducted. Findings Participants had relatively low levels of knowledge about paraffin-related safety. They had high levels of unsafe practice and their perceived risk of injury was moderate. Knowledge of paraffin safety and safe practices were positively correlated with each other. Greater knowledge showed a negative correlation with the perception of being at risk for injury, but safe practices showed no correlation with perceived risk of injury. Formal education, the number of children in the home and frequency of paraffin use were positively correlated with knowledge but not with safe practices. The only significant correlate to safe practices was greater income, perhaps a reflection of the impact of financial resources on paraffin safety practices. Conclusion To develop successful paraffin safety interventions, it is necessary to understand baseline levels of knowledge, practice and perceived risk of injury among at-risk populations. Our findings could be of value for designing interventions that will increase knowledge, improve safe practices and lead to the accurate perception of the risk of injury from using paraffin. PMID:19784450

  18. Comparing HIV-related symbolic stigma in six African countries: social representations in young people’s narratives

    PubMed Central

    Winskell, Kate; Hill, Elizabeth; Obyerodhyambo, Oby

    2011-01-01

    HIV-related symbolic stigma arises from moralistic value judgements attached to people living with HIV and has negative consequences from both public health and human rights perspectives. Relatively little is known about cross-national variation in symbolic stigma. With the purpose of informing stigma reduction efforts within and across settings, we compared social representations of HIV in six African countries with estimated adult HIV prevalence rates ranging from 1 to 33%. Our study used a unique data source, namely a stratified random sample (n=586, ~5%) from 11,354 creative ideas contributed from six countries to a continent-wide HIV-related scriptwriting contest held between February and April2005. The narratives were written by equal numbers of males and females aged 10–24 in urban and rural areas of Swaziland, Namibia, Kenya, South-East Nigeria, Burkina Faso and Senegal. We combined three analytical approaches: descriptive statistics on certain quantifiable characteristics of the narratives, thematic data analysis, and a narrative-based approach. The association of HIV with outsiders (“othering”)and preoccupation with the circumstances of infection are more common in lower prevalence countries but vary substantially in tone depending on the sociocultural context. The highest proportion both of moralising narratives and of narratives with pessimistic outcomes come from South-East Nigeria and, to a lesser extent, from Kenya, countries with prevalence levels of 3.9 and 6.1% respectively, in which evangelical Christian movements, including Pentecostalism, have sizeable followings. The data provide a rare cross-cultural overview of symbolic stigma, identify country-specific needs, and point to strategies for future programming. Social representations from the highest prevalence countries, Swaziland and Namibia, and from lower prevalence Burkina Faso offer potential models for the framing of HIV in ways that serve to increase social proximity and counteract

  19. Sexually Transmitted Infection Related Stigma and Shame Among African American Male Youth: Implications for Testing Practices, Partner Notification, and Treatment

    PubMed Central

    Lippman, Sheri A.; Philip, Susan; Bernstein, Kyle; Neilands, Torsten B.; Lightfoot, Marguerita

    2014-01-01

    Abstract A self-administered, street intercept survey was conducted in order to examine the relation of stigma and shame associated with sexually transmitted infections (STI) to STI testing practices, partner notification, and partner-delivered treatment among young African American men (n=108) in a low-income, urban community in San Francisco with high STI burden. Multivariate logistic regression revealed that increasing STI-related stigma was significantly associated with a decreased odds of STI testing, such that every standard deviation increase in stigma score was associated with 0.62 decreased odds of having been tested (aOR: 0.62, 95% CI: 0.38–1.00), controlling for age. STI stigma was also significantly associated with a decreased willingness to notify non-main partners of an STI (aOR: 0.64 95% CI: 0.41–0.99). Participants with higher levels of stigma and shame were also significantly less likely to be willing to deliver STI medication to a partner (stigma aOR: 0.57, 95% CI: 0.37–0.88; shame aOR 0.53 95% CI: 0.34–0.83). Findings suggest that STI-related stigma and shame, common in this population, could undermine STI testing, treatment, and partner notification programs. The medical establishment, one of the institutional factors to have reinforced this culture of stigma, must aid efforts to reduce its effects through providing integrated services, reframing sexual health in campaigns, educating clients, and providing wider options to aid disclosure and partner notification practices. PMID:25133501

  20. Multiple mantle upwellings in the transition zone beneath the northern East-African Rift system from relative P-wave travel-time tomography

    NASA Astrophysics Data System (ADS)

    Civiero, Chiara; Hammond, James O. S.; Goes, Saskia; Fishwick, Stewart; Ahmed, Abdulhakim; Ayele, Atalay; Doubre, Cecile; Goitom, Berhe; Keir, Derek; Kendall, J.-Michael; Leroy, Sylvie; Ogubazghi, Ghebrebrhan; Rümpker, Georg; Stuart, Graham W.

    2015-09-01

    Mantle plumes and consequent plate extension have been invoked as the likely cause of East African Rift volcanism. However, the nature of mantle upwelling is debated, with proposed configurations ranging from a single broad plume connected to the large low-shear-velocity province beneath Southern Africa, the so-called African Superplume, to multiple lower-mantle sources along the rift. We present a new P-wave travel-time tomography model below the northern East-African, Red Sea, and Gulf of Aden rifts and surrounding areas. Data are from stations that span an area from Madagascar to Saudi Arabia. The aperture of the integrated data set allows us to image structures of ˜100 km length-scale down to depths of 700-800 km beneath the study region. Our images provide evidence of two clusters of low-velocity structures consisting of features with diameter of 100-200 km that extend through the transition zone, the first beneath Afar and a second just west of the Main Ethiopian Rift, a region with off-rift volcanism. Considering seismic sensitivity to temperature, we interpret these features as upwellings with excess temperatures of 100 ± 50 K. The scale of the upwellings is smaller than expected for lower mantle plume sources. This, together with the change in pattern of the low-velocity anomalies across the base of the transition zone, suggests that ponding or flow of deep-plume material below the transition zone may be spawning these upper mantle upwellings. This article was corrected on 28 SEP 2015. See the end of the full text for details.

  1. Demanding kin relations and depressive symptoms among low-income African American women: mediating effects of self-esteem and optimism.

    PubMed

    Taylor, Ronald D; Budescu, Mia; McGill, Rebecca Kang

    2011-07-01

    Association of demanding kin relations, depressive symptoms, self-esteem, and optimism was assessed among 130 low-income African American women. Demanding relations with kin were positively associated with depressive symptoms and negatively linked to self-esteem and optimism. Self-esteem and optimism were negatively associated with depressive symptoms and mediated the association of demanding relations with kin and women's depressive symptoms. Findings were discussed in terms of the detrimental effects of demanding social relations with kin and the possible role that other relationships may play in compensating for poor relations with extended family.

  2. Efficacy of Orlistat as an Adjunct to Behavioral Treatment in Overweight African American and Caucasian Adolescents with Obesity-related Co-morbid Conditions

    PubMed Central

    McDuffie, Jennifer R.; Calis, Karim A.; Uwaifo, Gabriel I.; Sebring, Nancy G.; Fallon, Erica M.; Frazer, Teresa E; Hubbard, Van S.; Yanovski, Jack A.

    2012-01-01

    This pilot study compared the efficacy of orlistat as an adjunctive treatment for obesity between African American and Caucasian adolescents. 20 obese adolescents with obesity-related co-morbid conditions underwent measurements of body composition, glucose homeostasis by frequently sampled intravenous glucose tolerance test (FSIGT), and fasting lipids before and after 6-months’ treatment with orlistat 120mg TID in conjunction with a comprehensive behavioral program. Weight (p< 0.05), BMI (p<0.001), total cholesterol (p<0.001), LDL cholesterol (p<0.001), fasting insulin (p<0.02) and fasting glucose (p<0.003) were lower after treatment. Insulin sensitivity, measured during the FSIGT, improved significantly (p<0.02), as did fasting indices such as the homeostasis model assessment for insulin resistance (p<0.01). African American subjects exhibited significantly less improvement in weight (p<0.05), BMI (p<0.01), waist circumference (p=0.03), and insulin sensitivity (p=0.05). Improvements in cholesterol were not significantly different between African Americans and Caucasians. We conclude that Caucasians lost more weight and had greater improvements in insulin sensitivity than African Americans, but both exhibited improvements in plasma lipids. The true benefit of orlistat treatment over a comprehensive behavioral program remains to be determined in placebo-controlled trials. PMID:15112907

  3. A Structural Equation Model of HIV-Related Stigma, Racial Discrimination, Housing Insecurity and Wellbeing among African and Caribbean Black Women Living with HIV in Ontario, Canada

    PubMed Central

    Logie, Carmen H.; Jenkinson, Jesse I. R.; Earnshaw, Valerie; Tharao, Wangari; Loutfy, Mona R.

    2016-01-01

    African and Caribbean Black women in Canada have new HIV infection rates 7 times higher than their white counterparts. This overrepresentation is situated in structural contexts of inequities that result in social, economic and health disparities among African and Caribbean Black populations. Economic insecurity is a distal driver of HIV vulnerability, reducing access to HIV testing, prevention and care. Less is known about how economic insecurity indicators, such as housing security, continue to influence the lives of women living with HIV following HIV-positive diagnoses. The aim of this study was to test a conceptual model of the pathways linking HIV-related stigma, racial discrimination, housing insecurity, and wellbeing (depression, social support, self-rated health). We implemented a cross-sectional survey with African and Caribbean Black women living with HIV in 5 Ontario cities, and included 157 participants with complete data in the analyses. We conducted structural equation modeling using maximum likelihood estimation to evaluate the hypothesized conceptual model. One-fifth (22.5%; n = 39) of participants reported housing insecurity. As hypothesized, racial discrimination had significant direct effects on: HIV-related stigma, depression and social support, and an indirect effect on self-rated health via HIV-related stigma. HIV-related stigma and housing insecurity had direct effects on depression and social support, and HIV-related stigma had a direct effect on self-rated health. The model fit the data well: χ2 (45, n = 154) = 54.28, p = 0.387; CFI = 0.997; TLI = 0.996; RMSEA = 0.016. Findings highlight the need to address housing insecurity and intersecting forms of stigma and discrimination among African and Caribbean Black women living with HIV. Understanding the complex relationships between housing insecurity, HIV-related stigma, racial discrimination, and wellbeing can inform multi-level interventions to reduce stigma and enhance health. PMID

  4. Game auction prices are not related to biodiversity contributions of southern African ungulates and large carnivores.

    PubMed

    Dalerum, Fredrik; Miranda, Maria

    2016-01-01

    There is an urgent need for human societies to become environmentally sustainable. Because public policy is largely driven by economic processes, quantifications of the relationship between market prices and environmental values can provide important information for developing strategies towards sustainability. Wildlife in southern Africa is often privately owned and traded at game auctions to be utilized for commercial purposes mostly related to tourism. This market offers an interesting opportunity to evaluate how market prices relate to biologically meaningful species characteristics. In this market, prices were not correlated with species contributions to either phylogenetic or functional diversity, and species contributions to phylogenetic or functional diversity did not influence the trends in prices over time for the past 20 years. Since this economic market did not seem to appreciate evolutionary or ecologically relevant characteristics, we question if the game tourism market may contribute towards biodiversity conservation in southern Africa. We suggest that market prices in general may have limited values as guides for directing conservation and environmental management. We further suggest that there is a need to evaluate what humans value in biological organisms, and how potentially necessary shifts in such values can be instigated. PMID:26911226

  5. Relations between albedos and emissivities from MODIS and ASTER data over North African Desert

    NASA Astrophysics Data System (ADS)

    Zhou, L.; Dickinson, R. E.; Ogawa, K.; Tian, Y.; Jin, M.; Schmugge, T.; Tsvetsinskaya, E.

    2003-10-01

    This paper analyzes relations among MODIS surface albedos, ASTER broadband (3-14 μm) emissivities, and a soil taxonomy map over the arid areas of Algeria, Libya, and Tunisia in North Africa at 30 second (about 1 km) and 2 minute (about 4 km) spatial resolutions. The MODIS albedo data are from 7 spectral bands and 3 broadbands during dust-free seasons and the emissivity data are derived from a linear combination of the waveband emissivities of the ASTER five thermal infrared channels. Both albedo and emissivity data in the study region show similar considerable spatial variability, larger than assumed by most climate models, and such variability is related to the surface types (sands, rock, and soil orders). Emissivity over bare soils exhibits statistically significant correlations with albedos at both broadbands and most of spectral bands and decreases linearly with albedos. Albedo and emissivity are more strongly correlated with each other than either is to the surface types, apparently because of their higher resolution either spatially or in surface mineralogy. This paper provides guidance for the possible inclusion of such correlation to specify albedo and emissivity in climate models.

  6. Relations Between Albedos and Emissivities From MODIS and ASTER Data Over North African Desert

    NASA Astrophysics Data System (ADS)

    Zhou, L.; Dickinson, R.; Ogawa, K.; Tian, Y.; Jin, M.; Schmugge, T.; Tsvetsinskaya, E.

    2003-12-01

    This paper analyzes relations among MODIS surface albedos, ASTER broadband (3-14 μ m) emissivities, and a soil taxonomy map over the arid areas of Algeria, Libya, and Tunisia in North Africa at 30 second (about 1 km) and 2 minute (about 4 km) spatial resolutions. The MODIS albedo data are from 7 spectral bands and 3 broadbands during dust-free seasons and the emissivity data are derived from a linear combination of the waveband emissivities of the ASTER five thermal infrared channels. Both albedo and emissivity data in the study region show similar considerable spatial variability, larger than assumed by most climate models, and such variability is related to the surface types (sands, rock, and soil orders). Emissivity over bare soils exhibits statistically significant correlations with albedos at both broadbands and most of spectral bands and decreases linearly with albedos. Albedo and emissivity are more strongly correlated with each other than either is to the surface types, apparently because of their higher resolution either spatially or in surface mineralogy. This paper provides guidance for the possible inclusion of such correlation to specify albedo and emissivity in climate models.

  7. Game auction prices are not related to biodiversity contributions of southern African ungulates and large carnivores

    PubMed Central

    Dalerum, Fredrik; Miranda, Maria

    2016-01-01

    There is an urgent need for human societies to become environmentally sustainable. Because public policy is largely driven by economic processes, quantifications of the relationship between market prices and environmental values can provide important information for developing strategies towards sustainability. Wildlife in southern Africa is often privately owned and traded at game auctions to be utilized for commercial purposes mostly related to tourism. This market offers an interesting opportunity to evaluate how market prices relate to biologically meaningful species characteristics. In this market, prices were not correlated with species contributions to either phylogenetic or functional diversity, and species contributions to phylogenetic or functional diversity did not influence the trends in prices over time for the past 20 years. Since this economic market did not seem to appreciate evolutionary or ecologically relevant characteristics, we question if the game tourism market may contribute towards biodiversity conservation in southern Africa. We suggest that market prices in general may have limited values as guides for directing conservation and environmental management. We further suggest that there is a need to evaluate what humans value in biological organisms, and how potentially necessary shifts in such values can be instigated. PMID:26911226

  8. East African Rift

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Places where the earth's crust has formed deep fissures and the plates have begun to move apart develop rift structures in which elongate blocks have subsided relative to the blocks on either side. The East African Rift is a world-famous example of such rifting. It is characterized by 1) topographic deep valleys in the rift zone, 2) sheer escarpments along the faulted walls of the rift zone, 3) a chain of lakes within the rift, most of the lakes highly saline due to evaporation in the hot temperatures characteristic of climates near the equator, 4) voluminous amounts of volcanic rocks that have flowed from faults along the sides of the rift, and 5) volcanic cones where magma flow was most intense. This example in Kenya displays most of these features near Lake Begoria.

    The image was acquired December 18, 2002, covers an area of 40.5 x 32 km, and is located at 0.1 degrees north latitude, 36.1 degrees east longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  9. What some African development plans say on population related issues in development.

    PubMed

    1983-01-01

    This discussion reviews what development plans say about population related issues in development in the countries of Botswana, Kenya, Lesotho, Senegal, Nigeria, Ivory Coast, Seychelles, Sierra Leone, Somalia Democratic Republic, Sudan, The United Republic of Cameroon, Tanzania, Zambia, and Zimbabwe. Botswana's 1970-73 development plan recognized the need to have fewer children who would be better fed, well clothed, properly housed, and better educated. The government set a target of population growth not to exceed 2.5% for the 1970-80 period. The government of Kenya has expressed much concern about population growth and is devoted to continuing and strengthening the official family planning program instituted in 1967. Lesotho's 1980-81 to 1984-85 development plan emphasizes the need to enhance the well-being of the rural population. The orientation of the health sector strategy is towards primary health care, health education, family planning, water supply, sanitation, and nutrition. Nigeria's 1975-80 plan indicates that demographic factors do not appear as yet to constitute a significant or serious obstacle to domestic economic progress. The objective of the Ivory Coast's 1976-80 plan for economic, social, and cultural development is to increase population since the Ivory Coast still seems to be an underpopulated country. The 1979-83 National Development Plan of Seychelles includes the following objectives: to remedy the housing problem, to achieve full employment, and to introduce responsible family planning. Sierra Leone's development plan for 1974-75 to 1978-79 did not indicate a need to decrease population growth. Population variables in relation to development are not well articulated in the plan of the Somalia Democratic Republic. Like many other developing countries, Sudan's plan has objectives to improve all aspects of the standard of living. It recognizes the serious problem of absorbing a larger population in urban areas. In Tanzania family planning is

  10. Energy, protein, and zinc nutriture of rural African children in relation to some anthropometric indices

    SciTech Connect

    Ferguson, E.L.; Gibson, R.S.; Osei-Opare, F.; Opare-Obisaw, C.; Thompson, L.U. Univ. of Ghana, Legon Univ. of Toronto, Ontario )

    1991-03-11

    Heights, weights, arm circumferences, and triceps skinfold thicknesses of 66 Malawian and 148 Ghanaian preschool children were measured during 3 seasons. Their seasonal energy, protein, Ca, Zn, dietary fiber and phytate intakes were estimated from 3-day weighed records, using analyzed and literature food composition values. Seasonal hair Zn concentrations were analyzed by instrumental neutron activation analyses, The mean annual intakes for Malawian compared to Ghanaian children were higher for energy protein, and Zn. Cereals contributed a higher proportion of the total energy intake in the Malawian compared to the Ghanaian diets. A higher percentage of the Malawian children had height-for-age Z-scores below {minus}2SD, but a lower percentage had weight-for-height Z-scores below {minus}1SD compared to their Ghanaian counterparts. These differences may, in part be related to the high cereal intakes of the Malawian children.

  11. Secondary metabolites and nutrients of woody plants in relation to browsing intensity in African savannas.

    PubMed

    Scogings, Peter F; Hjältén, Joakim; Skarpe, Christina

    2011-12-01

    Carbon-based secondary metabolites (CBSMs) are assumed to function as defences that contribute to herbivore-avoidance strategies of woody plants. Severe browsing has been reported to reduce concentrations of CBSMs and increase N concentrations in individual plants, causing heavily browsed plants to be characterised by N-rich/C-poor tissues. We hypothesised that concentrations of condensed tannins (CT) and total polyphenols (TP) should decrease, or N increase, in relation to increasing intensity of browsing, rendering severely browsed plants potentially more palatable (increased N:CT) and less N-limited (increased N:P) than lightly browsed ones. We sampled naturally browsed trees (taller than 2 m) of four abundant species in southern Kruger National Park, South Africa. Species-specific relationships between N:CT, CT, TP and P concentrations and increasing browsing intensity were detected, but N and N:P were consistently invariable. We developed a conceptual post-hoc model to explain diverse species-specific CBSM responses on the basis of relative allocation of C to total C-based defence traits (e.g. spines/thorns, tough/evergreen leaves, phenolic compounds). The model suggests that species with low allocation of C to C-based defence traits become C-limited (potentially more palatable) at higher browsing intensity than species with high allocation of C to C-based defences. The model also suggests that when N availability is high, plants become C-limited at higher browsing intensity than when N availability is low. PMID:21660581

  12. Associations between Common Variants in Iron-Related Genes with Haematological Traits in Populations of African Ancestry

    PubMed Central

    Tanaka, Toshiko; Towers, G. Wayne; Verhoef, Hans; Veenemans, Jacobien; Talsma, Elise F.; Harryvan, Jan; Boekschoten, Mark V.; Feskens, Edith J.; Melse-Boonstra, Alida

    2016-01-01

    Background Large genome-wide association (GWA) studies of European ancestry individuals have identified multiple genetic variants influencing iron status. Studies on the generalizability of these associations to African ancestry populations have been limited. These studies are important given interethnic differences in iron status and the disproportionate burden of iron deficiency among African ancestry populations. Methods We tested the associations of 20 previously identified iron status-associated single nucleotide polymorphisms (SNPs) in 628 Kenyans, 609 Tanzanians, 608 South Africans and 228 African Americans. In each study, we examined the associations present between 20 SNPs with ferritin and haemoglobin, adjusting for age, sex and CRP levels. Results In the meta analysis including all 4 African ancestry cohorts, we replicated previously reported associations with lowered haemoglobin concentrations for rs2413450 (β = -0.19, P = 0.02) and rs4820268 (β = -0.16, P = 0.04) in TMPRSS6. An association with increased ferritin concentrations was also confirmed for rs1867504 in TF (β = 1.04, P = <0.0001) in the meta analysis including the African cohorts only. Conclusions In all meta analyses, we only replicated 4 of the 20 single nucleotide polymorphisms reported to be associated with iron status in large GWA studies of European ancestry individuals. While there is now evidence for the associations of a number of genetic variants with iron status in both European and African ancestry populations, the considerable lack of concordance highlights the importance of continued ancestry-specific studies to elucidate the genetic underpinnings of iron status in ethnically diverse populations. PMID:27332551

  13. African hot spot volcanism: small-scale convection in the upper mantle beneath cratons.

    PubMed

    King, S D; Ritsema, J

    2000-11-10

    Numerical models demonstrate that small-scale convection develops in the upper mantle beneath the transition of thick cratonic lithosphere and thin oceanic lithosphere. These models explain the location and geochemical characteristics of intraplate volcanos on the African and South American plates. They also explain the presence of relatively high seismic shear wave velocities (cold downwellings) in the mantle transition zone beneath the western margin of African cratons and the eastern margin of South American cratons. Small-scale, edge-driven convection is an alternative to plumes for explaining intraplate African and South American hot spot volcanism, and small-scale convection is consistent with mantle downwellings beneath the African and South American lithosphere. PMID:11073447

  14. Two jacalin-related lectins from seeds of the African breadfruit (Treculia africana L.).

    PubMed

    Shimokawa, Michiko; Nsimba-Lubaki, Shadrack Makuta; Hayashi, Namiko; Minami, Yuji; Yagi, Fumio; Hiemori, Keiko; Tateno, Hiroaki; Hirabayashi, Jun

    2014-01-01

    Two jacalin-related lectins (JRLs) were purified by mannose-agarose and melibiose-agarose from seeds of Treculia africana. One is galactose-recognizing JRL (gJRL), named T. africana agglutinin-G (TAA-G), and another one is mannose-recognizing JRL (mJRL), TAA-M. The yields of the two lectins from the seed flour were approximately 7.0 mg/g for gJRL and 7.2 mg/g for mJRL. The primary structure of TAA-G was determined by protein sequencing of lysyl endopeptic peptides and chymotryptic peptides. The sequence identity of TAA-G to other gJRLs was around 70%. Two-residue insertion was found around the sugar-binding sites, compared with the sequences of other gJRLs. Crystallographic studies on other gJRLs have shown that the primary sugar-binding site of gJRLs can accommodate Gal, GalNAc, and GalNAc residue of T-antigen (Galβ1-3GalNAcα-). However, hemagglutination inhibition and glycan array showed that TAA-G did not recognize GalNAc itself and T-antigen. TAA-G preferred melibiose and core 3 O-glycan.

  15. Two jacalin-related lectins from seeds of the African breadfruit (Treculia africana L.).

    PubMed

    Shimokawa, Michiko; Nsimba-Lubaki, Shadrack Makuta; Hayashi, Namiko; Minami, Yuji; Yagi, Fumio; Hiemori, Keiko; Tateno, Hiroaki; Hirabayashi, Jun

    2014-01-01

    Two jacalin-related lectins (JRLs) were purified by mannose-agarose and melibiose-agarose from seeds of Treculia africana. One is galactose-recognizing JRL (gJRL), named T. africana agglutinin-G (TAA-G), and another one is mannose-recognizing JRL (mJRL), TAA-M. The yields of the two lectins from the seed flour were approximately 7.0 mg/g for gJRL and 7.2 mg/g for mJRL. The primary structure of TAA-G was determined by protein sequencing of lysyl endopeptic peptides and chymotryptic peptides. The sequence identity of TAA-G to other gJRLs was around 70%. Two-residue insertion was found around the sugar-binding sites, compared with the sequences of other gJRLs. Crystallographic studies on other gJRLs have shown that the primary sugar-binding site of gJRLs can accommodate Gal, GalNAc, and GalNAc residue of T-antigen (Galβ1-3GalNAcα-). However, hemagglutination inhibition and glycan array showed that TAA-G did not recognize GalNAc itself and T-antigen. TAA-G preferred melibiose and core 3 O-glycan. PMID:25155899

  16. HIV-Related Discrimination among Grade Six Students in Nine Southern African Countries

    PubMed Central

    Maughan-Brown, Brendan; Spaull, Nicholas

    2014-01-01

    Background HIV-related stigmatisation and discrimination by young children towards their peers have important consequences at the individual level and for our response to the epidemic, yet research on this area is limited. Methods We used nationally representative data to examine discrimination of HIV-positive children by grade six students (n = 39,664) across nine countries in Southern Africa: Botswana, Lesotho, Malawi, Mozambique, Namibia, South Africa, Swaziland, Zambia and Zimbabwe. Descriptive statistics are used to compare discrimination by country, gender, geographic location and socioeconomic status. Multivariate logistic regression is employed to assess potential determinants of discrimination. Results The levels and determinants of discrimination varied significantly between the nine countries. While one in ten students in Botswana, Malawi, South Africa and Swaziland would “avoid or shun” an HIV positive friend, the proportions in Lesotho, Mozambique, Zambia and Zimbabwe were twice as high (approximately 20%). A large proportion of students believed that HIV positive children should not be allowed to continue to attend school, particularly in Zambia (33%), Lesotho (37%) and Zimbabwe (42%). The corresponding figures for Malawi and Swaziland were significantly lower at 13% and 12% respectively. Small differences were found by gender. Children from rural areas and poorer schools were much more likely to discriminate than those from urban areas and wealthier schools. Importantly, we identified factors consistently associated with discrimination across the region: students with greater exposure to HIV information, better general HIV knowledge and fewer misconceptions about transmission of HIV via casual contact were less likely to report discrimination. Conclusions Our study points toward the need for early interventions (grade six or before) to reduce stigma and discrimination among children, especially in schools situated in rural areas and poorer

  17. Incidence and determinants of nevirapine and efavirenz-related skin rashes in West Africans: nevirapine's epitaph?

    PubMed

    Sarfo, Fred Stephen; Sarfo, Maame Anima; Norman, Betty; Phillips, Richard; Chadwick, David

    2014-01-01

    Non-nucleoside reverse transcriptase inhibitor (NNRTI) associated rash is common and frequently leads to discontinuation of NNRTIs. This study assessed the risk of developing rashes and discontinuing NNRTIs and associated factors in a large clinic in central Ghana. In this retrospective cohort study, clinical data were obtained in patients starting efavirenz or nevirapine between 2004-2010. Factors associated with rashes were explored using a multivariate Cox proportional hazards regression model. Of 3,999 patients who started NNRTI-based ART, 281 (7.0%) experienced at least one episode of NNRTI-related rash with an incidence of 2.63 events/100 person-years, occurring in 10.2% and 5.6% of patients taking nevirapine and efavirenz respectively. Most rashes (94%) were grade 1 or 2 and were reported a median of 2 months following initiation of ART. In multivariate analysis developing a rash was associated with nevirapine use (aHR 1.67, 95% CI 1.28-2.10), female gender (aHR of 1.39, 95% CI 1.01-1.92) and lower baseline CD4 counts (aHR 0.88, 95% CI 0.82-0.95 per 50 cells/mm³ increment). Patients with nevirapine-associated rash were 11 times more likely to discontinue treatment as patients with efavirenz-associated rash. In contrast to findings in other studies, NNRTI-associated rashes in Ghanaians appear more common in patients with lower baseline CD4 counts. Given the increased frequency of rashes with nevirapine and subsequent discontinuations in many patients, along with other treatment-limiting toxicities, this provides further impetus for the replacement of nevirapine by efavirenz as the first-line NNRTI treatment of choice in Africa. PMID:24728406

  18. Incidence and Determinants of Nevirapine and Efavirenz-Related Skin Rashes in West Africans: Nevirapine's Epitaph?

    PubMed Central

    Sarfo, Fred Stephen; Sarfo, Maame Anima; Norman, Betty; Phillips, Richard; Chadwick, David

    2014-01-01

    Non-nucleoside reverse transcriptase inhibitor (NNRTI) associated rash is common and frequently leads to discontinuation of NNRTIs. This study assessed the risk of developing rashes and discontinuing NNRTIs and associated factors in a large clinic in central Ghana. In this retrospective cohort study, clinical data were obtained in patients starting efavirenz or nevirapine between 2004–2010. Factors associated with rashes were explored using a multivariate Cox proportional hazards regression model. Of 3,999 patients who started NNRTI-based ART, 281 (7.0%) experienced at least one episode of NNRTI-related rash with an incidence of 2.63 events/100 person-years, occurring in 10.2% and 5.6% of patients taking nevirapine and efavirenz respectively. Most rashes (94%) were grade 1 or 2 and were reported a median of 2 months following initiation of ART. In multivariate analysis developing a rash was associated with nevirapine use (aHR 1.67, 95% CI 1.28–2.10), female gender (aHR of 1.39, 95% CI 1.01–1.92) and lower baseline CD4 counts (aHR 0.88, 95% CI 0.82–0.95 per 50 cells/mm3 increment). Patients with nevirapine-associated rash were 11 times more likely to discontinue treatment as patients with efavirenz-associated rash. In contrast to findings in other studies, NNRTI-associated rashes in Ghanaians appear more common in patients with lower baseline CD4 counts. Given the increased frequency of rashes with nevirapine and subsequent discontinuations in many patients, along with other treatment-limiting toxicities, this provides further impetus for the replacement of nevirapine by efavirenz as the first-line NNRTI treatment of choice in Africa. PMID:24728406

  19. Mat-related sedimentary structures in Neoproterozoic peritidal passive margin deposits of the West African Craton (Anti-Atlas, Morocco)

    NASA Astrophysics Data System (ADS)

    Bouougri, E.; Porada, H.

    2002-11-01

    Proterozoic inliers in the central Anti-Atlas mountains expose predominantly siliciclastic sedimentary successions deposited in peritidal zones along the Neoproterozoic continental margin of the West African Craton (WAC). The low-grade metamorphic and modestly deformed sediments contain a wealth of sedimentary structures related to the former presence and activities of microbial mats and respective physicobiological processes. The well-preserved structures include wrinkle structures, erosion marks, microbial sand chips, spindle-shaped and subcircular microbial shrinkage cracks, and possibly gas domes and cabbage-head structures. Thin sections exhibit mat fragments and dispersed grains of hematite/limonite after pyrite in fine-grained quartzitic storm deposits. Post-storm layers frequently consist of matrix-supported sand-sized to silt-sized grains and are overlain by argillaceous veneers including isolated silt-sized grains and black carbonaceous laminae. The muddy veneers are considered to represent compacted stacks of microbial mats (biolaminites), which colonized and biostabilized storm and post-storm layers, and thus prevented them from eroding. In the absence of grazing and burrowing organisms and at suitable depositional and hydrodynamic conditions, it may be expected that Proterozoic microbial mats extensively grew from the supratidal to the intertidal zones and occasionally, e.g. behind protective barriers, in the subtidal zone and beyond. Mat-related structures, however, need specific conditions for their formation and preservation: Wrinkle structures, erosion marks, and microbial sand chips require tractional currents and soon deposition and burial, respectively. Such conditions are preferably met in intertidal and supratidal zones. Spindle-shaped and subcircular cracks require mat shrinkage due to either desiccation or "syneresis". Crack propagation implies progressive shrinkage, while superposition of crack generations indicates repeated alternation

  20. Reduced reproductive function in wild baboons (Papio hamadryas anubis) related to natural consumption of the African black plum (Vitex doniana).

    PubMed

    Higham, James P; Ross, Caroline; Warren, Ymke; Heistermann, Michael; MacLarnon, Ann M

    2007-09-01

    Several authors have suggested that the consumption of plant compounds may have direct effects on wild primate reproductive biology, but no studies have presented physiological evidence of such effects. Here, for two troops of olive baboons (Papio hamadryas anubis) at Gashaka-Gumti National Park, Nigeria, we show major seasonal increases in levels of fecal progesterone metabolites in females, and provide evidence that this is linked to the consumption of natural plant compounds. Increases in fecal progestogen excretion occurred seasonally in all females, in all reproductive states, including lactation. Detailed feeding data on the study animals showed that only one food species is consumed by both troops at the time of observed progestogen peaks, and at no other times of the year: the African black plum, Vitex doniana. Laboratory tests demonstrated the presence of high concentrations of progestogen-like compounds in V. doniana. Together with published findings linking the consumption of a related Vitex species (Vitex agnus castus) to increased progestogen levels in humans, our data suggest that natural consumption of V. doniana was a likely cause of the observed increases in progestogens. Levels of progestogen excretion in the study baboons during periods of V. doniana consumption are higher than those found during pregnancy, and prevent the expression of the sexual swelling, which is associated with ovulatory activity. As consortship and copulatory activity in baboons occur almost exclusively in the presence of a sexual swelling, V. doniana appears to act on cycling females as both a physiological contraceptive (simulating pregnancy in a similar way to some forms of the human contraceptive pill) and a social contraceptive (preventing sexual swelling, thus reducing association and copulation with males). The negative effects of V. doniana on reproduction may be counter-balanced by the wide-range of medicinal properties attributed to plants in this genus. This is

  1. Tectonic Plate Movement.

    ERIC Educational Resources Information Center

    Landalf, Helen

    1998-01-01

    Presents an activity that employs movement to enable students to understand concepts related to plate tectonics. Argues that movement brings topics to life in a concrete way and helps children retain knowledge. (DDR)

  2. Negro, Black, Black African, African Caribbean, African American or what? Labelling African origin populations in the health arena in the 21st century

    PubMed Central

    Agyemang, C.; Bhopal, R.; Bruijnzeels, M.

    2005-01-01

    Broad terms such as Black, African, or Black African are entrenched in scientific writings although there is considerable diversity within African descent populations and such terms may be both offensive and inaccurate. This paper outlines the heterogeneity within African populations, and discusses the strengths and limitations of the term Black and related labels from epidemiological and public health perspectives in Europe and the USA. This paper calls for debate on appropriate terminologies for African descent populations and concludes with the proposals that (1) describing the population under consideration is of paramount importance (2) the word African origin or simply African is an appropriate and necessary prefix for an ethnic label, for example, African Caribbean or African Kenyan or African Surinamese (3) documents should define the ethnic labels (4) the label Black should be phased out except when used in political contexts. PMID:16286485

  3. Negro, Black, Black African, African Caribbean, African American or what? Labelling African origin populations in the health arena in the 21st century.

    PubMed

    Agyemang, Charles; Bhopal, Raj; Bruijnzeels, Marc

    2005-12-01

    Broad terms such as Black, African, or Black African are entrenched in scientific writings although there is considerable diversity within African descent populations and such terms may be both offensive and inaccurate. This paper outlines the heterogeneity within African populations, and discusses the strengths and limitations of the term Black and related labels from epidemiological and public health perspectives in Europe and the USA. This paper calls for debate on appropriate terminologies for African descent populations and concludes with the proposals that (1) describing the population under consideration is of paramount importance (2) the word African origin or simply African is an appropriate and necessary prefix for an ethnic label, for example, African Caribbean or African Kenyan or African Surinamese (3) documents should define the ethnic labels (4) the label Black should be phased out except when used in political contexts. PMID:16286485

  4. Charts relating the compressive buckling stress of longitudinally supported plates to the effective deflectional and rotational stiffness of the supports

    NASA Technical Reports Server (NTRS)

    Anderson, Roger A; Semonian, Joseph W

    1954-01-01

    A stability analysis is made of a long flat rectangular plate subjected to a uniform longitudinal compressive stress and supported along its longitudinal edges and along one or more longitudinal lines by elastic line supports. The elastic supports possess deflectional and rotational stiffness. Such configuration is an idealization of the compression cover skin and internal structure of a wing and tail surfaces. The results of the analysis are presented in the form of charts in which the buckling-stress coefficient is plotted against the buckle length of the plate for a wide range of support stiffnesses. The charts make possible the determination of the compressive buckling stress of plates supported by members whose stiffness may or may not be defined by elementary beam bending and twisting theory but yet whose effective restraint is amenable to evaluation. The deflectional and rotational stiffness provided by longitudinal stiffeners and full-depth webs is discussed and numerical examples are given to illustrate the application of the charts to the design of wing structures.

  5. Trajectories of Intrusive Parenting During Infancy and Toddlerhood as Predictors of Rural, Low-Income African American Boys’ School-Related Outcomes

    PubMed Central

    Clincy, Amanda R.; Mills-Koonce, W. Roger

    2015-01-01

    Stability and change in maternal intrusiveness during early childhood is rarely explored, particularly within African American families. The current study examined the prediction of maternal intrusiveness during the first 3 years of life among mothers of rural, low-income African American boys and its relation to school-related outcomes. Observations of mothers (N=230) interacting with children at 6, 24, and 36 months were coded and analyzed. Predictors of the trajectories and child outcomes were assessed using questionnaires and various tasks. On average, mothers of African American boys increased in intrusiveness across the first 3 years of life. Cumulative sociodemographic risk was associated with initial levels of intrusiveness, and child fearfulness and maternal negative regard predicted increases in intrusiveness overtime. After controlling for sociodemographic risk, child temperament, and parental negativity, increases in intrusiveness over the first 3 years of life were associated with lower levels of expressive communication, inhibitory control, and intellectual functioning but not with attention focusing. Comprehensive parenting intervention efforts aimed toward improving children’s outcomes must take into consideration the broader socioeconomic and affective context in which parenting behaviors occur, as well as stability and change in parenting over time. PMID:23889012

  6. Using a cultural framework to assess the nutrition influences in relation to birth outcomes among African American women of childbearing age: application of the PEN-3 theoretical model.

    PubMed

    Kannan, Srimathi; Webster, Dewitt; Sparks, Arlene; Acker, Charlene M; Greene-Moton, Ella; Tropiano, Elizabeth; Turner, Tonya

    2009-07-01

    The purpose is to present the process and results of focus groups conducted to access information for the design of a healthy eating curriculum to reduce maternal nutritional risks and enhance protective factors among African American women in relation to birth outcomes. Sixteen younger (19 to 25 years) and 20 older African American women (45 to 60 years), respectively, participated. The PEN-3 model, (Airhihenbuwa, 1995, 1999) guided the focus groups. Most women stated that culture and family relationships impacted their food choices. Younger women expressed creativity with recipes and presented a desire to be more involved with preparing foods. Older women expressed eagerness to teach family-centered culinary skill-building classes. Both groups of women acknowledged time and budget barriers, identified the prevalence of lactose intolerance, and recognized that large grocery stores that offered food variety were not located in their community. Health professionals are encouraged to consider these findings while designing interventions targeting young African American women's nutrition in relation to birth outcomes.

  7. Polymorphisms of Estrogen Metabolism-Related Genes and Prostate Cancer Risk in Two Populations of African Ancestry

    PubMed Central

    Emeville, Elise; Ferdinand, Séverine; Punga, Augustin; Lufuma, Simon; Blanchet, Pascal; Romana, Marc; Multigner, Luc

    2016-01-01

    Background Estrogens are thought to play a critical role in prostate carcinogenesis. It has been suggested that polymorphisms of genes encoding enzymes involved in estrogen metabolism are risk factors for prostate cancer. However, few studies have been performed on populations of African ancestry, which are known to have a high risk of prostate cancer. Objective We investigated whether functional polymorphisms of CYP17, CYP19, CYP1B1, COMT and UGT1A1 affected the risk of prostate cancer in two different populations of African ancestry. Methods In Guadeloupe (French West Indies), we compared 498 prostate cancer patients and 565 control subjects. In Kinshasa (Democratic Republic of Congo), 162 prostate cancer patients were compared with 144 controls. Gene polymorphisms were determined by the SNaPshot technique or short tandem repeat PCR analysis. Logistic regression was used to estimate adjusted odds ratios (OR) and 95% confidence intervals (CI). Results The AA genotype and the A allele of rs4680 (COMT) appeared to be inversely associated with the risk of prostate cancer in adjusted models for both Afro-Caribbean and native African men. For the A allele, a significant inverse association was observed among cases with low-grade Gleason scores and localized clinical stage, in both populations. Conclusions These preliminary results support the hypothesis that polymorphisms of genes encoding enzymes involved in estrogen metabolism may modulate the risk of prostate cancer in populations of African ancestry. PMID:27074016

  8. The Relations Between Maternal Expressed Emotion and Children's Perceived Self-Competence, Behavior and Intelligence in African-American Families

    ERIC Educational Resources Information Center

    Kwon, Julie; Delaney-Black, Virginia; Covington, Chandice; Abell, Steven C.; Nordstrom-Bailey, Beth; Sokol, Robert J.; Ager, Joel

    2006-01-01

    This study examined the relationship between maternal expressed emotion (EE) and children's perceived self-competence, behavior and intelligence in a community sample of 190 urban, African American children ages 6-7. Maternal EE was measured by the Five Minute Speech Sample. Self reports and standardized measures were used to examine other mother…

  9. Sharing Information about Peer Relations: Parent and Adolescent Opinions and Behaviors in Hmong and African American Families

    ERIC Educational Resources Information Center

    Brown, B. Bradford; Bakken, Jeremy P.; Nguyen, Jacqueline; Von Bank, Heather G.

    2007-01-01

    Despite sharing similar attitudes regarding the information about peers that parents have a right to know, the strategies African American and Hmong families use to seek or censor information about peers diverge because of ethnic differences in emphasis on trust, nurturing autonomy, respect for parental authority, and maintaining cultural…

  10. Cultural Learning Context as It Relates to Efficacy and the Mathematics Performance of African-American Middle School Students

    ERIC Educational Resources Information Center

    Burrell, Jennifer O.

    2012-01-01

    Nearly 20 years of empirical work has demonstrated that cultural-asset focused learning environments can improve the academic performance of African-American students. One example is communal learning context, which shifts students' motivational primacy from the individual to the social group. Considering the critical role of efficacy beliefs in…

  11. African American Single Mothers: Understanding Their Lives and Families. Sage Series on Race and Ethnic Relations, Volume 10.

    ERIC Educational Resources Information Center

    Dickerson, Bette J.

    Past research on African American single mothers and their families has been conducted using conventional paradigms based upon models of the dominant culture. This practice has resulted in the creation of stereotypes and misconceptions about "the Black family." In this collection of original work by an interdisciplinary group of scholars, the…

  12. Ethnic Identity in African American and European American Preadolescents: Relation to Self-Worth, Social Goals, and Aggression

    ERIC Educational Resources Information Center

    Holmes, Khiela J.; Lochman, John E.

    2009-01-01

    The current study tested models to determine the extent to which self-worth and social goals mediate the influence of ethnic identity on aggression among aggressive European and African American preadolescents. Ethnic identity emerged as important for both groups, but in different ways. Different patterns of influence of ethnic identity and of…

  13. The Relations of Stressful Events and Nonacademic Future Expectations in African American Adolescents: Gender Differences in Parental Monitoring

    ERIC Educational Resources Information Center

    Cunningham, Michael; Mars, Dustin E.; Burns, Lateela J.

    2012-01-01

    Urban African American high school students (N = 206) completed a study to examine gender differences in parental monitoring and the effect on the relationship between exposure to stressful life events and nonacademic future expectations. Participant's ages range from 13 to 18 (M = 15.78, SD = 1.19). Participants reported high exposure to…

  14. Maternal Control and Sensitivity, Child Gender, and Maternal Education in Relation to Children's Behavioral Outcomes in African American Families

    ERIC Educational Resources Information Center

    Tamis-LeMonda, Catherine S.; Briggs, Rahil D.; McClowry, Sandra G.; Snow, David L.

    2009-01-01

    This study examined relationships between mother-child interactions and children's behaviors in 119 urban African American mothers and their 6-7 year old children. Interactions during a cooking task and a follow-up child clean-up task were videotaped. Principal components analyses of behaviors during the cooking task yielded two factors in mothers…

  15. Adiposity and hyperglycaemia in pregnancy and related health outcomes in European ethnic minorities of Asian and African origin: a review

    PubMed Central

    Jenum, Anne Karen; Sommer, Christine; Sletner, Line; Mørkrid, Kjersti; Bærug, Anne; Mosdøl, Annhild

    2013-01-01

    Background Ethnic minorities in Europe have high susceptibility to type 2 diabetes (T2DM) and, in some groups, also cardiovascular disease (CVD). Pregnancy can be considered a stress test that predicts future morbidity patterns in women and that affects future health of the child. Objective To review ethnic differences in: 1) adiposity, hyperglycaemia, and pre-eclampsia during pregnancy; 2) future risk in the mother of obesity, T2DM and CVD; and 3) prenatal development and possible influences of maternal obesity, hyperglycaemia, and pre-eclampsia on offspring's future disease risk, as relevant for ethnic minorities in Europe of Asian and African origin. Design Literature review. Results Maternal health among ethnic minorities is still sparsely documented. Higher pre-pregnant body mass index (BMI) is found in women of African and Middle Eastern descent, and lower BMI in women from East and South Asia compared with women from the majority population. Within study populations, risk of gestational diabetes mellitus (GDM) is considerably higher in many minority groups, particularly South Asians, than in the majority population. This increased risk is apparent at lower BMI and younger ages. Women of African origin have higher risk of pre-eclampsia. A GDM pregnancy implies approximately seven-fold higher risk of T2DM than normal pregnancies, and both GDM and pre-eclampsia increase later risk of CVD. Asian neonates have lower birth weights, and mostly also African neonates. This may translate into increased risks of later obesity, T2DM, and CVD. Foetal overgrowth can promote the same conditions. Breastfeeding represents a possible strategy to reduce risk of T2DM in both the mother and the child. Conclusions Ethnic minority women in Europe with Asian and African origin and their offspring seem to be at increased risk of T2DM and CVD, both currently and in the future. Pregnancy is an important window of opportunity for short and long-term disease prevention. PMID:23467680

  16. Slab dragging and the recent geodynamic evolution of the western Mediterranean plate boundary region

    NASA Astrophysics Data System (ADS)

    Spakman, Wim; Chertova, Maria V.; van den Berg, Arie P.; Thieulot, Cedric; van Hinsbergen, Douwe J. J.

    2016-04-01

    The Tortonian-Present geodynamic evolution of the plate boundary between North Africa and Iberia is characterized by first-order enigmas. This concerns, e.g., the diffuse tectonic activity of the plate boundary; the crustal thickening below the Rif; the closing of the northern Moroccan marine gateways prior to the Messinian Salinity Crisis; crustal extension of the central to eastern Betics; the origin and sense of motion of the large left-lateral Trans Alboran Shear Zone (TASZ) and Eastern Betic Shear Zone (EBSZ); and lithosphere delamination of the North African continental edge. Many explanations have been given for each of these seemingly disparate tectonic features, which invariably have been addressed in the plate tectonic context of the NW-SE relative plate convergence between the major plates since the Tortonian, mostly independently from each other. Usually there is no clear role for the subducted slab underlying the region, except for presumed rollback, either to SW or to the W, depending on the type of observations that require explanation. Here we integrate the dynamic role of the slab with the NW-SE relative plate convergence by 3-D numerical modelling of the slab evolution constrained by absolute plate motions (Chertova et al., JGR,2014 & Gcubed 2014). By combining observations and predictions from seismology, geology, and geodesy, with our numerical 3-D slab-mantle dynamics modelling, we developed a new and promising geodynamic framework that provides explanations of all noted tectonic enigmas in a coherent and connected way. From the Tortonian until today, we propose that mantle-resisted slab dragging combines with the NW-SE plate convergence across the (largely) unbroken plate boundary to drive the crustal deformation of the region. Slab dragging is the lateral transport, pushing or pulling, of slab through the mantle by the absolute motion of the subducting plate (Chertova et al., Gcubed, 2014). Because the slab is connected to both the Iberian

  17. A new model for the Paleogene motion of Greenland relative to North America: Plate reconstructions of the Davis Strait and Nares Strait regions between Canada and Greenland

    NASA Astrophysics Data System (ADS)

    Oakey, Gordon N.; Chalmers, James A.

    2012-10-01

    A simplified plate kinematic model for the Paleogene motion of Greenland relative to North America has been developed to provide a new framework for modeling the oceanic spreading system in Baffin Bay and the intraplate tectonic development of the Davis Strait and Nares Strait regions of the Arctic. A single Euler rotation pole was calculated for the C13N to C24N Eocene motion of the Greenland Plate relative to North America using spreading centers and fracture zones interpreted from satellite derived gravity data in Baffin Bay combined with fracture zones in Labrador Sea from published sources. A single stage pole is proposed for the C25N to C27N portion of the Paleocene and a short-lived stage pole was found necessary to accommodate the C24N to C25N interval. This kinematic model has been used to reinterpret published shipborne magnetic profiles in central Baffin Bay to reveal a Paleocene spreading center and limits of both Eocene and Paleocene oceanic crust. Aeromagnetic data over northeastern Baffin Bay have been used to identify a new fracture zone in northern Baffin Bay. Plate reconstructions are presented incorporating constraints on plate boundaries from onshore and offshore geological and geophysical mapping. Within the Davis Strait, Paleocene oceanic crust was emplaced in an elongated rift that was subsequently inverted by approximately 300 km of Eocene transpression along the Ungava Fault Zone. In the Nares Strait Region, a "microplate" scenario is presented to explain the simultaneous formation of the Lancaster Sound Rift Basin and complex deformation within the Eurekan Orogenic Belt.

  18. Macrobrecciation at a Plate Boundary: The Iskenderun Block

    NASA Astrophysics Data System (ADS)

    Sine, C. R.; Brumbaugh, D. S.

    2004-12-01

    The area of intersection of the East Anatolian and the Dead Sea fault zones in southeast Turkey and northwest Syria represents the intersection of three tectonic Plates: African,Anatolian, and Arabian. Widespread deformation occurs in the area of the plate triple junction including the presence of multiple faults bounding plate fragments along the plate tectonic boundaries. Earthquake fault plane solutions and epicenter clustering in the area of the intersectiong fault zones has been used to identify plate fragments. This study delineates a plate boundary near the mouth of the Gulf of Iskenderun based on linear trends in epicenters and the orientation of fault plane solution nodal planes. The boundary located near the mouth of the Gulf of Iskenderun is proposed to be the southern boundary of a plate fragment roughly the size of the state of Delaware, herein named the Iskenderun block. Plate motions and moho depths suggest that the Iskenderun block is a promontory that was originally joined to the African plate and has been caught up in the deformation at the Anatolian-Arabian-African triple junction and has been subsequently torn from the African plate.

  19. HIV-Related Medical Admissions to a South African District Hospital Remain Frequent Despite Effective Antiretroviral Therapy Scale-Up

    PubMed Central

    Meintjes, Graeme; Kerkhoff, Andrew D.; Burton, Rosie; Schutz, Charlotte; Boulle, Andrew; Van Wyk, Gavin; Blumenthal, Liz; Nicol, Mark P.; Lawn, Stephen D.

    2015-01-01

    Abstract The public sector scale-up of antiretroviral therapy (ART) in South Africa commenced in 2004. We aimed to describe the hospital-level disease burden and factors contributing to morbidity and mortality among hospitalized HIV-positive patients in the era of widespread ART availability. Between June 2012 and October 2013, unselected patients admitted to medical wards at a public sector district hospital in Cape Town were enrolled in this cross-sectional study with prospective follow-up. HIV testing was systematically offered and HIV-infected patients were systematically screened for TB. The spectrum of admission diagnoses among HIV-positive patients was documented, vital status at 90 and 180 days ascertained and factors independently associated with death determined. Among 1018 medical admissions, HIV status was ascertained in 99.5%: 60.1% (n = 609) were HIV-positive and 96.1% (n = 585) were enrolled. Of these, 84.4% were aware of their HIV-positive status before admission. ART status was naive in 35.7%, current in 45.0%, and interrupted in 19.3%. The most frequent primary clinical diagnoses were newly diagnosed TB (n = 196, 33.5%), other bacterial infection (n = 100, 17.1%), and acquired immunodeficiency syndrome (AIDS)-defining illnesses other than TB (n = 64, 10.9%). By 90 days follow-up, 175 (29.9%) required readmission and 78 (13.3%) died. Commonest causes of death were TB (37.2%) and other AIDS-defining illnesses (24.4%). Independent predictors of mortality were AIDS-defining illnesses other than TB, low hemoglobin, and impaired renal function. HIV still accounts for nearly two-thirds of medical admissions in this South African hospital and is associated with high mortality. Strategies to improve linkage to care, ART adherence/retention and TB prevention are key to reducing HIV-related hospitalizations in this setting. PMID:26683950

  20. Fault-related Soil Efflux of Mantle-derived CO2 in the Magadi and Natron Basins, East African Rift

    NASA Astrophysics Data System (ADS)

    Lee, H.; Muirhead, J.; Fischer, T. P.; Kattenhorn, S. A.; Ebinger, C. J.; Thomas, N.; Kianji, G.; Onguso, B.; Maqway, M. D.

    2014-12-01

    The Magadi (Kenya) and Natron (Tanzania) basins of the East African Rift are in an early stage (< 7 Ma) of continental rifting. The many normal faults observed in these areas create sediment-filled basins and a large number of alkaline springs feed water into two major lakes (Lake Magadi and Natron). Earthquake swarms reported in 1998 (Magadi) and 2007 (Natron) were accompanied by surface ruptures. Although CO2 is a major component of magmatic volatiles and fault-related fluids that may facilitate earthquakes and fault weakening, the soil CO2 efflux of continental rifts is poorly known. Here, we report soil CO2 flux rates measured in the Magadi and Natron basins, and carbon isotope values (δ13C, ‰ vs. PDB) to constrain CO2sources. Soil CO2 fluxes were measured at fault zones, horsts, grabens, and surface ruptures by EGM-4 (PP systems) with a gas accumulation chamber. A t-shaped connector with a needle was used for gas sampling into evacuated glass vials with a rubber septum. δ13C values were measured by isotope ratio mass spectrometer with a gas bench at the stable isotope laboratory, University of New Mexico. The fault zones in the Magadi basin have higher maximum CO2 flux rates (< 533.52 g m-2 d-1) and heavier δ13C values (< -3.8 ‰) than the Natron basin (< 147.12 g m-2 d-1 and < -6.2 ‰, respectively). In both areas, soil CO2 efflux is insignificant (< 10 g m-2 d-1) in both horsts and the middle of grabens with lighter δ 13C values (~ -10 ‰) likely resulting from significant air contribution. The highest CO2 flux rates (< 919.44 g m-2 d-1) were measured at recent surface ruptures, but they have lighter δ13C values (-10 to -15 ‰), implying significant air and biogenic C contributions. Our results indicate that (1) normal faults are pathways that deliver mantle-derived CO2 to the surface, (2) the Magadi basin exhibits greater mantle-derived CO2 than the Natron basin, and (3) recent ruptures are zones of shallow CO2 degassing.

  1. The Development and Evaluation of a Portion Plate for Youth: A Pilot Study

    ERIC Educational Resources Information Center

    Bohnert, Amy M.; Randall, Edin T.; Tharp, Stephanie; Germann, Julie

    2011-01-01

    Objective: To develop and evaluate a portion plate for adolescents (Nutri-plate). Methods: Sixteen African American adolescents (mean age = 12.94 years; 66% male) were randomized to participate in either plate design or nutrition education sessions. Adolescents' input was used to create the Nutri-plate, and participants' food selection and intake…

  2. Extraordinary high ductility/strength of the interface designed bulk W-ZrC alloy plate at relatively low temperature

    PubMed Central

    Xie, Z. M.; Liu, R.; Miao, S.; Yang, X. D.; Zhang, T.; Wang, X. P.; Fang, Q. F.; Liu, C. S.; Luo, G. N.; Lian, Y. Y.; Liu, X.

    2015-01-01

    The refractory tungsten alloys with high ductility/strength/plasticity are highly desirable for a wide range of critical applications. Here we report an interface design strategy that achieves 8.5 mm thick W-0.5 wt. %ZrC alloy plates with a flexural strength of 2.5 GPa and a strain of 3% at room temperature (RT) and ductile-to-brittle transition temperature of about 100 °C. The tensile strength is about 991 MPa at RT and 582 MPa at 500 °C, as well as total elongation is about 1.1% at RT and as large as 41% at 500 °C, respectively. In addition, the W-ZrC alloy plate can sustain 3.3 MJ/m2 thermal load without any cracks. This processing route offers the special coherent interfaces of grain/phase boundaries (GB/PBs) and the diminishing O impurity at GBs, which significantly strengthens GB/PBs and thereby enhances the ductility/strength/plasticity of W alloy. The design thought can be used in the future to prepare new alloys with higher ductility/strength. PMID:26531172

  3. Extraordinary high ductility/strength of the interface designed bulk W-ZrC alloy plate at relatively low temperature

    NASA Astrophysics Data System (ADS)

    Xie, Z. M.; Liu, R.; Miao, S.; Yang, X. D.; Zhang, T.; Wang, X. P.; Fang, Q. F.; Liu, C. S.; Luo, G. N.; Lian, Y. Y.; Liu, X.

    2015-11-01

    The refractory tungsten alloys with high ductility/strength/plasticity are highly desirable for a wide range of critical applications. Here we report an interface design strategy that achieves 8.5 mm thick W-0.5 wt. %ZrC alloy plates with a flexural strength of 2.5 GPa and a strain of 3% at room temperature (RT) and ductile-to-brittle transition temperature of about 100 °C. The tensile strength is about 991 MPa at RT and 582 MPa at 500 °C, as well as total elongation is about 1.1% at RT and as large as 41% at 500 °C, respectively. In addition, the W-ZrC alloy plate can sustain 3.3 MJ/m2 thermal load without any cracks. This processing route offers the special coherent interfaces of grain/phase boundaries (GB/PBs) and the diminishing O impurity at GBs, which significantly strengthens GB/PBs and thereby enhances the ductility/strength/plasticity of W alloy. The design thought can be used in the future to prepare new alloys with higher ductility/strength.

  4. The interpretation of crustal dynamics data in terms of plate interactions and active tectonics of the Anatolian plate and surrounding regions in the Middle East

    NASA Technical Reports Server (NTRS)

    Toksoz, M. Nafi; Reilinger, Robert

    1992-01-01

    A detailed study was made of the consequences of the Arabian plate convergence against Eurasia and its effects on the tectonics of Anatolia and surrounding regions of the eastern Mediterranean. A primary source of information is time rates of change of baseline lengths and relative heights determined by repeated SLR measurements. These SLR observations are augmented by a network of GPS stations in Anatolia, Aegea, and Greece, established and twice surveyed since 1988. The existing SLR and GPS networks provide the spatial resolution necessary to reveal the details of ongoing tectonic processes in this area of continental collision. The effort has involved examining the state of stress in the lithosphere and relative plate motions as revealed by these space based geodetic measurements, seismicity, and earthquake mechanisms as well as the aseismic deformations of the plates from conventional geodetic data and geological evidence. These observations are used to constrain theoretical calculations of the relative effects of: (1) the push of the Arabian plate; (2) high topography of Eastern Anatolia; (3) the geometry and properties of African-Eurasian plate boundary; (4) subduction under the Hellenic Arc and southwestern Turkey; and (5) internal deformation and rotation of the Anatolian plate.

  5. Is Loss of Fixation Following Locked Plating of Proximal Humeral Fractures Related to the Number of Screws and Their Positions in the Humeral Head?

    PubMed Central

    Maddah, Mohammad; Prall, Wolf C.; Geyer, Lucas; Wirth, Stefan; Mutschler, Wolf; Ockert, Ben

    2014-01-01

    The aim of the study was to examine the correlation between the chosen position of screws and the complications observed in patients who underwent locked plating of proximal humeral fractures. We evaluated radiographs of 367 patients treated by locked-plating for proximal humeral fractures. Radiographs were taken at one day, 6 weeks, 3 months and 6 months after surgery, and were analyzed for secondary fracture displacement, loss of fixation, cutting out of screws and necrosis of the humeral head. Secondary loss of fixation occurred in 58 cases (15.8%) and among those cutting out of screws was observed in 25 cases (6.8%). In cases of secondary loss of fixation a mean of 6.7 screws were used to fix the fracture (vs 6.6, P=0.425). There was neither significant correlation between position of screws and the occurrence of postoperative loss of fixation in Spearman correlation nor relationship from backward logistic regression analysis. Loss of fixation following locked plating of proximal humeral fractures does not relate to the number of screws and their positions in the humeral head. In consequence, anatomic fracture reduction and restoration of the humeral head-shaft angle are still important factors and should not be disregarded. PMID:25002940

  6. Relation of Serum Fetuin-A Levels to Coronary Artery Calcium in African-American Patients on Chronic Hemodialysis

    PubMed Central

    Zheng, Sijie; de las Fuentes, Lisa; Bierhals, Andrew; Ash-Bernal, Rachel; Spence, Karen; Slatopolsky, Eduardo; Davila-Roman, Victor G.; Delmez, James

    2008-01-01

    Vascular calcium deposition in end-stage renal disease occurs commonly, however its relationship to cardiovascular risk factors and fetuin-A levels in African-Americans is not known. Compliant African-American HD patients (n=17) agreed to undergo a 64-slice multidetector computed tomography for the assessment of coronary artery calcium score (CACS). The relationship between traditional cardiovascular risk factors (i.e., age, gender, dialysis vintage, history of diabetes, means of the previous 3 years of the weekly pre-dialysis blood pressure and hemoglobin, means of monthly values of calcium, phosphorus, alkaline phosphatase, uric acid and albumin, and means of quarterly measures of parathyroid hormone and lipids), and fetuin-A levels and CACS was explored by univariate analyses. Serum phosphorus levels over the previous 3 years were well controlled. The CACS range was 0-3,877 Agatston units (mean: 996; median :196). Among the tested variables, only fetuin-A was significantly and inversely associated with CACS (standardized β = -0.64 [95% confidence limits [CL]: -18.09, -3.62], p=0.006). There was no association between age and fetuin-A level (standardized β = -0.02 [95%CL: -0.10, 0.23]). In conclusion, African-American patients on long-term HD and with good phosphorus control exhibit a strong inverse correlation between fetuin-A levels and CACS which is independent of age. PMID:19101228

  7. Lohse's historic plate archive

    NASA Astrophysics Data System (ADS)

    Tsvetkov, M.; Tsvetkova, K.; Richter, G.; Scholz, G.; Böhm, P.

    The description and the analysis of Oswald Lohse's astrophotographic plates, collected at the Astrophysical Observatory Potsdam in the period 1879 - 1889, are presented. 67 plates of the archive, taken with the greatest instrument of the observatory at that time - the refractor (D = 0.30 m, F = 5.40 m, scale = 38''/mm) and with the second heliographic objective (D = 0.13 m, F = 1.36 m, scale = 152''/mm) - - survived two world wars in relative good condition. The plate emulsions are from different manufacturers in the beginning of astrophotography (Gädicke, Schleussner, Beernaert, etc.). The sizes of the plates are usually 9x12 cm2, which corresponds to fields of 1.2deg and 5deg respectively for each instrument mentioned above. The average limiting magnitude is 13.0(pg). Besides of the plates received for technical experiments (work on photographic processes, testing of new instruments and methods of observations), the scientific observations follow programs for studies of planet surfaces, bright stars, some double stars, stellar clusters and nebulous objects. Lohse's archive is included into the Wide Field Plate Database (http://www.skyarchive.org) as the oldest systematic one, covering the fields of Orion (M42/43), Pleiades, h & chi Persei, M37, M3, M11, M13, M92, M31, etc. With the PDS 2020 GM+ microdensitometer of Münster University 10 archive plates were digitized.

  8. Correlation between plate motions and tectonic subsidence of sedimentary basins in Africa

    SciTech Connect

    Janssen, M.E. )

    1993-09-01

    From the early Mesozoic until the Holocene, the African continent was generally in a state of extension, based on plate tectonic reconstructions and sedimentary basin subsidence studies. Beginning with the breakup of Gondwana in the Permian-Triassic, this resulted in the formation of the present-day African continental margins and a series of intracontinental rift basins, located mainly on older (late Proterozoic) shear zones. Numerous wells from marginal, as well as intracontinental rift basins, have been backstripped to elucidate their Mesozoic and Tertiary tectonic histories. They show a generally consistent patterns of subsidence and uplift phases in all basins. During the evolution of these basins, the direction of African plate motion changed several times. This was related to the differential opening of the central and south Atlantic oceans, changes in spreading rates in both the Atlantic and Indian oceans, and the collision between Africa and Europe. Episodes of compressional deformation related to these plate tectonic changes are revealed in backstripped tectonic subsidence curves.

  9. Caribbean plate interactions

    SciTech Connect

    Ball, M. )

    1993-02-01

    Vector analysis of plate motions, derived from studies of Atlantic magnetic lineations and fracture zone trends, indicates the following relative movements between the Caribbean, North American, and South American Plates. (1) During Early Jurassic to Early Cretaceous, the North American Plate moved 1900 km westward and 900 km northward relative to the South American Plate. A broad zone including the Caribbean region, i.e., the zone between the North and South America Plates, was a site of left-lateral shear and north-south extension. (2) During Early Cretaceous to Late Cretaceous, the North American Mate moved an additional 1200 km westward relative to South America across this zone. (3) During Late Cretaceous to the end of the Eocene, the North American Plate moved 200 km westward and 400 km northward relative to the South American Plate. (4) From the end of the Eocene to near the end of the Miocene, North America converged on South America some 200 km and moved 100 km eastward relative to it. Through the Mesozoic and earliest Tertiary history of the Caribbean, the region was a shear zone within which left-lateral displacement exceeded 3000 km and north-south extension exceeded 1300 km. In regard to time, 80% of the history of the Caribbean region is one of north-south extension and left-lateral shear. In terms of space, 97% of the shear is left-lateral and the ratio of divergence versus convergence is 7 to 1. Thus, characterizing the Caribbean region, and the Atlantic to its east, as a zone of north-south extension and left-lateral shear, is a fair generalization.

  10. Violin plate modes.

    PubMed

    Gough, Colin

    2015-01-01

    As the first step toward developing a generic model for the acoustically radiating vibrational modes of the violin and related instruments, the modes of both freely supported and edge-constrained top and back plates have been investigated as functions of shape, arching height, elastic anisotropy, the f-holes and associated island area, thickness graduations, and the additional boundary constraints of the ribs, soundpost, and bass-bar present in the assembled instrument. Comsol shell structure finite element software has been used as a quasi-experimental tool, with physical and geometric properties varied smoothly, often over several orders of magnitude, allowing the development of the plate modes to be followed continuously from those of an initially square plate to those of doubly-arched, guitar-shaped, orthotropic plates and their dependence on all the above factors. PMID:25618046

  11. Violin plate modes.

    PubMed

    Gough, Colin

    2015-01-01

    As the first step toward developing a generic model for the acoustically radiating vibrational modes of the violin and related instruments, the modes of both freely supported and edge-constrained top and back plates have been investigated as functions of shape, arching height, elastic anisotropy, the f-holes and associated island area, thickness graduations, and the additional boundary constraints of the ribs, soundpost, and bass-bar present in the assembled instrument. Comsol shell structure finite element software has been used as a quasi-experimental tool, with physical and geometric properties varied smoothly, often over several orders of magnitude, allowing the development of the plate modes to be followed continuously from those of an initially square plate to those of doubly-arched, guitar-shaped, orthotropic plates and their dependence on all the above factors.

  12. Relative humidity effects on the surface electrical properties of resistive plate chamber melaminic laminates uncoated and coated with polymerized linseed oil film

    SciTech Connect

    Bearzotti, Andrea; Palummo, Lucrezia

    2007-09-15

    Relative humidity is an important quantity to control in many manufacturing environments such as semiconductor industry. Humidity and moisture can affect many electronic devices, generally rendering their operation worse. In this study we present results showing that in some specific applications, humidity can improve the performance of an electronic device. Resistive plate chambers are used as trigger detectors of the muon system in LHC (large hadron collider) experiments ATLAS (a toroidal LHC apparatus), CMS (compact muon solenoid) and ALICE (a large ion collider experiment) and as detector in cosmic rays experiment ARGO (astrophysical radiation with ground-based observatory). These detectors are made of phenolic-melaminic laminate electrodes, coated with a polymerized linseed oil film delimiting the gaseous sensitive volume. The loss of some of the detector capability can be progressive in time and due to the intrinsic limits of the detector materials. One of these effects is due to an increase of the total plate resistance, that is correlated to ion migration and relativity humidity phenomena. Our purpose is to understand the relative humidity (RH) influence on the conduction mechanisms on the electrodes surface. Results of amperometric measurements on laminate samples kept at a fixed temperature of 22 deg. C, cycling RH between 10% and 90% are here presented.

  13. The Relationship Between the Social Environment and Lifestyle-Related Physical Activity in a Low-Income African American Inner-City Southern Neighborhood.

    PubMed

    Andersen, Lori; Gustat, Jeanette; Becker, Adam B

    2015-10-01

    The social ecological model was used to examine individual, interpersonal, and neighborhood characteristics related to lifestyle-related physical activity (PA) in a low-income African American (AA) population in New Orleans, Louisiana. Interviewers administered surveys to randomly-sampled household participants from three low-income, AA neighborhoods in New Orleans, Louisiana. Questions included the social and physical environment, physical activity, interpersonal factors, demographics, height and weight. Logistic regression multivariable models were built predicting whether the respondent met PA guidelines, controlling for neighborhood. Females were less as likely to engage in lifestyle-related PA compared to males (OR 0.46, CI 0.30-0.70). Support specific for PA was correlated with engaging in lifestyle-related PA (OR 1.45, CI 1.14-1.83). The individual and social environment should be considered for increasing PA in AA. Interventions targeting the AA population could consider ways of enhancing social support for PA.

  14. The pisiform growth plate is lost in humans and supports a role for Hox in growth plate formation

    PubMed Central

    Kjosness, Kelsey M; Hines, Jasmine E; Lovejoy, C Owen; Reno, Philip L

    2014-01-01

    The human pisiform is a small, nodular, although functionally significant, bone of the wrist. In most other mammals, including apes and Australopithecus afarensis, pisiforms are elongate. An underappreciated fact is that the typical mammalian pisiform forms from two ossification centers. We hypothesize that: (i) the presence of a secondary ossification center in mammalian pisiforms indicates the existence of a growth plate; and (ii) human pisiform reduction results from growth plate loss. To address these hypotheses, we surveyed African ape pisiform ossification and confirmed the presence of a late-forming secondary ossification center in chimpanzees and gorillas. Identification of the initial ossification center occurs substantially earlier in apes relative to humans, raising questions concerning the homology of the human pisiform and the two mammalian ossification centers. Second, we conducted histological and immunohistochemical analyses of pisiform ossification in mice. We confirm the presence of two ossification centers separated by organized columnar and hypertrophic chondrocyte zones. Flattened chondrocytes were highly mitotic, indicating the presence of a growth plate. Hox genes have been proposed to play a fundamental role in growth plate patterning. The existence of a pisiform growth plate presents an interesting test case for the association between Hox expression and growth plate formation, and could explain the severe effects on the pisiform observed in Hoxa11 and Hoxd11 knockout mice. Consistent with this hypothesis, we show that Hoxd11 is expressed adjacent to the pisiform in late-stage embryonic mouse limbs supporting a role for Hox genes in growth plate specification. This raises questions concerning the mechanisms regulating Hox expression in the developing carpus. PMID:25279687

  15. How mantle slabs drive plate tectonics.

    PubMed

    Conrad, Clinton P; Lithgow-Bertelloni, Carolina

    2002-10-01

    The gravitational pull of subducted slabs is thought to drive the motions of Earth's tectonic plates, but the coupling between slabs and plates is not well established. If a slab is mechanically attached to a subducting plate, it can exert a direct pull on the plate. Alternatively, a detached slab may drive a plate by exciting flow in the mantle that exerts a shear traction on the base of the plate. From the geologic history of subduction, we estimated the relative importance of "pull" versus "suction" for the present-day plates. Observed plate motions are best predicted if slabs in the upper mantle are attached to plates and generate slab pull forces that account for about half of the total driving force on plates. Slabs in the lower mantle are supported by viscous mantle forces and drive plates through slab suction. PMID:12364804

  16. How mantle slabs drive plate tectonics.

    PubMed

    Conrad, Clinton P; Lithgow-Bertelloni, Carolina

    2002-10-01

    The gravitational pull of subducted slabs is thought to drive the motions of Earth's tectonic plates, but the coupling between slabs and plates is not well established. If a slab is mechanically attached to a subducting plate, it can exert a direct pull on the plate. Alternatively, a detached slab may drive a plate by exciting flow in the mantle that exerts a shear traction on the base of the plate. From the geologic history of subduction, we estimated the relative importance of "pull" versus "suction" for the present-day plates. Observed plate motions are best predicted if slabs in the upper mantle are attached to plates and generate slab pull forces that account for about half of the total driving force on plates. Slabs in the lower mantle are supported by viscous mantle forces and drive plates through slab suction.

  17. An Introduction to West African Literature.

    ERIC Educational Resources Information Center

    Taiwo, Oladele

    Intended to provide help for those interested in studying West African literature, this book is divided into three parts. Part One provides background information: the various African oral traditions are discussed, related to the way of life of the people, and examined for the extent to which they form the basis of present West African literary…

  18. Complex Syntax Production of African American Preschoolers.

    ERIC Educational Resources Information Center

    Jackson, Sandra C.; Roberts, Joanne E.

    2001-01-01

    This study examined changes in the complex syntax production of 85 African American preschoolers and the role of child (gender, age, African American English) and family (home environment) factors. Age, gender, and home environment effects were found for the amount of complex language used. African American English was not related to amount of…

  19. Experiences of racial discrimination and relation to sexual risk for HIV among a sample of urban black and African American men.

    PubMed

    Reed, E; Santana, M C; Bowleg, L; Welles, S L; Horsburgh, C R; Raj, A

    2013-04-01

    This study aimed to examine racial discrimination and relation to sexual risk for HIV among a sample of urban black and African American men. Participants of this cross-sectional study were black and African American men (N = 703) between the ages of 18 and 65 years, recruited from four urban clinical sites in the northeast. Multivariate logistic regression models were used to analyze the relation of reported racial discrimination to the following: (1) sex trade involvement, (2) recent unprotected sex, and (3) reporting a number of sex partners in the past 12 months greater than the sample average. The majority of the sample (96%) reported racial discrimination. In adjusted analyses, men reporting high levels of discrimination were significantly more likely to report recent sex trade involvement (buying and/or selling) (adjusted odds ratio (AOR) range = 1.7-2.3), having recent unprotected vaginal sex with a female partner (AOR = 1.4, 95% confidence interval (CI), 1.1-2.0), and reporting more than four sex partners in the past year (AOR = 1.4, 95% CI, 1.1-1.9). Findings highlight the link between experiences of racial discrimination and men's sexual risk for HIV.

  20. REDUCED GLUTEAL EXPRESSION OF ADIPOGENIC AND LIPOGENIC GENES IN BLACK SOUTH AFRICAN WOMEN IS ASSOCIATED WITH OBESITY-RELATED INSULIN RESISTANCE

    PubMed Central

    Goedecke, Julia H.; Evans, Juliet; Keswell, Dheshnie; Stimson, Roland H.; Livingstone, Dawn E.W.; Hayes, Philip; Adams, Kevin; Dave, Joel A.; Victor, Hendriena; Levitt, Naomi S.; Lambert, Estelle V.; Walker, Brian R.; Seckl, Jonathan R.; Olsson, Tommy; Kahn, Steven E.

    2014-01-01

    Context Black South African women are less insulin sensitive than their white counterparts, despite less central and greater peripheral fat deposition. We hypothesized that this paradox may be explained, in part, by differences in the adipogenic capacity of subcutaneous adipose tissue (SAT). Objective To measure adipogenic and lipogenic gene expression in abdominal and gluteal SAT depots, and determine their relationships with insulin sensitivity (SI) in South African women. Design Cross-sectional. Participants 14 normal-weight (BMI <25 kg/m2) black, 13 normal-weight white, 14 obese (BMI >30 kg/m2) black and 13 obese white premenopausal South African women. Main outcomes SI (frequently sampled intravenous glucose tolerance test) in relation to expression of adipogenic and lipogenic genes in abdominal and gluteal SAT depots. Results With increasing BMI, black women had less visceral fat (P=0.03) and more abdominal (P=0.017) and gynoid (P=0.041) SAT but had lower SI (P<0.01) than white women. The expression of adipogenic and lipogenic genes was proportionately lower with obesity in black, but not white women in the gluteal and deep SAT depots (P<0.05 for ethnicity x BMI effect). In black women only, the expression of these genes correlated positively with SI (all P<0.05), independently of age and fat mass. Conclusions Obese black women have reduced SAT expression of adipogenic and lipogenic genes compared to white women, which associates with reduced SI. These findings suggest that obesity in black women impairs SAT adipogenesis and storage, potentially leading to insulin resistance and increased risk of type 2 diabetes. PMID:21956425

  1. Relation of clinical, echocardiographic and electrocardiographic features of cardiac amyloidosis to the presence of the transthyretin V122I allele in older African-American men.

    PubMed

    Jacobson, Daniel; Tagoe, Clement; Schwartzbard, Arthur; Shah, Alan; Koziol, James; Buxbaum, Joel

    2011-08-01

    Previous studies have shown that 3% to 4% of African Americans carry an amyloidogenic allele of the human serum protein transthyretin (TTR V122I). The allele appears to have an absolute anatomic risk for cardiac amyloid deposition after 65 years of age. In this study, a case-control comparison was performed of clinical, echocardiographic, and electrocardiographic characteristics of 23 age at risk carriers of the amyloidogenic allele and 46 age-, gender-, and ethnically matched noncarriers being evaluated for cardiac disease using standard clinical testing. The 2 groups were matched for blood pressure and the cardiac ejection fraction. None of the subjects had a prestudy diagnosis of cardiac amyloidosis. Carriers of the amyloidogenic allele were found to have statistically significant increases in the occurrence of many of the echocardiographic features of cardiac amyloidosis relative to the noncarriers and a higher frequency of congestive heart failure and atrial fibrillation. The observations suggest that TTR V122I represents a substantial risk for clinically significant cardiac amyloidosis in elderly African American men, behaving as an age-dependent autosomal dominant disease-associated allele. The diagnosis is difficult to make but can be suspected in African Americans aged >60 years on the basis of age, echocardiographic evidence of diastolic dysfunction, and interventricular septal thickening, even in the absence of more recently available sophisticated echocardiographic techniques for evaluating long-axis function and cardiac magnetic resonance imaging. Positive results for the amyloidogenic TTR V122I allele support the diagnosis and define the origin of the disease, which can be confirmed by endomyocardial biopsy. PMID:21600538

  2. Bibliometric Assessment of European and Sub-Saharan African Research Output on Poverty-Related and Neglected Infectious Diseases from 2003 to 2011

    PubMed Central

    Gurney, Karen A.; Mgone, Charles S.

    2015-01-01

    Background The European & Developing Countries Clinical Trials Partnership (EDCTP) is a partnership of European and sub-Saharan African countries that aims to accelerate the development of medical interventions against poverty-related diseases (PRDs). A bibliometric analysis was conducted to 1) measure research output from European and African researchers on PRDs, 2) describe collaboration patterns, and 3) assess the citation impact of clinical research funded by EDCTP. Methodology/Principal Findings Disease-specific research publications were identified in Thomson Reuters Web of Science using search terms in titles, abstracts and keywords. Publication data, including citation counts, were extracted for 2003–2011. Analyses including output, share of global papers, normalised citation impact (NCI), and geographical distribution are presented. Data are presented as five-year moving averages. European EDCTP member countries accounted for ~33% of global research output in PRDs and sub-Saharan African countries for ~10% (2007–2011). Both regions contributed more to the global research output in malaria (43.4% and 22.2%, respectively). The overall number of PRD papers from sub-Saharan Africa increased markedly (>47%) since 2003, particularly for HIV/AIDS (102%) and tuberculosis (TB) (81%), and principally involving Southern and East Africa. For 2007–2011, European and sub-Saharan African research collaboration on PRDs was highly cited compared with the world average (NCI in brackets): HIV/AIDS 1.62 (NCI: 1.16), TB 2.11 (NCI: 1.06), malaria 1.81 (NCI: 1.22), and neglected infectious diseases 1.34 (NCI: 0.97). The NCI of EDCTP-funded papers for 2003–2011 was exceptionally high for HIV/AIDS (3.24), TB (4.08) and HIV/TB co-infection (5.10) compared with global research benchmarks (1.14, 1.05 and 1.35, respectively). Conclusions The volume and citation impact of papers from sub-Saharan Africa has increased since 2003, as has collaborative research between Europe and

  3. Eclogites and related metamorphism in the North America-Caribbean plate boundary: An example from the Motagua fault zone, Guatemala (Invited)

    NASA Astrophysics Data System (ADS)

    Tsujimori, T.; Hernandez Pineda, G. A.

    2009-12-01

    Active volcanic arcs and strike-slip fault systems characterize the present-day Caribbean Plate margins. The northern boundary of the Caribbean plate in Guatemala is the Motagua fault zone (MFZ). Along the MFZ in central and eastern Guatemala, eclogite- and jadeitite-bearing serpentinite-matrix mélange are exposed stretching ˜200 km on either side of the Motagua-Polochic fault system. The MFZ eclogites and related high-pressure metamorphic rocks represent key evidence for testing existing competing Caribbean plate tectonic models (e.g., Harlow et al., 2008, GSA Abs. Prog. 40:452). The presence of lawsonite-eclogite and jadeite-eclogite with lawsonite-blueschist-facies overprinting in the south of the MFZ (Tsujimori et al., 2006, GSA Spec. Paper 403:147-68) indicates that the geotherm in the paleo-subduction zone is very low. Protoliths for these high-pressure rocks consist of uppermost oceanic crust including MORB-origin greenstones and cherts with minor trench turbidites. Epidote-paragonite-eclogites of layered gabbroic origin occur in the north of the MFZ. Although some N-MFZ eclogites record amphibolite-facies hydration and new mineral growth, eclogitic garnets preserve lawsonite-pseudomorph and glaucophane, suggesting a cold subduction zone. The lack of ubiquitous lawsonite in northern eclogites may be attributed to due to water under-saturated conditions. Considering recent geochronology that implies a coeval eclogite-facies metamorphism at ˜130 Ma (Bruekener et al., 2009, EPSL284:228-35) and petrologic similarities of host serpentinized spinel-lherzolite on either side of the MFZ, we can tentatively reconstruct the succession of a fragmented eclogite-facies metamorphosed oceanic crust. However, the correct interpretation of the paleo-subduction record and further understanding of a cold subduction-zone process at paleo-Caribbean plate margin requires a more comprehensive approach to focus on in-situ geochemical and isotopic analyses of prograde metamorphic

  4. Ion plating for the future

    NASA Technical Reports Server (NTRS)

    Spalvins, T.

    1981-01-01

    The ion plating techniques are classified relative to the instrumental set up, evaporation media, and mode of transport. A distinction is drawn between the low vacuum (plasma) and high vacuum (ion beam) techniques. Ion plating technology is discussed at the fundamental and industrial level. At the fundamental level, the capabilities and limitations of the plasma (evaporant flux) and film characteristics are evaluated. And on the industrial level, the performance and potential uses of ion plated films are discussed.

  5. Making sense of condoms: social representations in young people’s HIV-related narratives from six African countries

    PubMed Central

    Winskell, Kate; Obyerodhyambo, Oby; Stephenson, Rob

    2011-01-01

    Condoms are an essential component of comprehensive efforts to control the HIV epidemic, both for those who know their status and for those who do not. Although young people account for almost half of all new HIV infections, reported condom use among them remains low in many sub-Saharan African countries. In order to inform education and communication efforts to increase condom use, we examined social representations of condoms among young people aged 10–24 in six African countries/regions with diverse HIV prevalence rates: Swaziland, Namibia, Kenya, South-East Nigeria, Burkina Faso, and Senegal. We used a unique data source, namely 11,354 creative ideas contributed from these countries to a continent-wide scriptwriting contest, held from 1st February to 15th April 2005, on the theme of HIV/AIDS. We stratified each country sample by the sex, age (10–14, 15–19, 20–24), and urban/rural location of the author and randomly selected up to 10 narratives for each of the 12 resulting strata, netting a total sample of 586 texts for the six countries. We analyzed the narratives qualitatively using thematic data analysis and narrative-based methodologies. Differences were observed across settings in the prominence accorded to condoms, the assessment of their effectiveness, and certain barriers to and facilitators of their use. Moralization emerged as a key impediment to positive representations of condoms, while humour was an appealing means to normalize them. The social representations in the narratives identify communication needs in and across settings and provide youth-focused ideas and perspectives to inform future intervention efforts. PMID:21388731

  6. Making sense of condoms: social representations in young people's HIV-related narratives from six African countries.

    PubMed

    Winskell, Kate; Obyerodhyambo, Oby; Stephenson, Rob

    2011-03-01

    Condoms are an essential component of comprehensive efforts to control the HIV epidemic, both for those who know their status and for those who do not. Although young people account for almost half of all new HIV infections, reported condom use among them remains low in many sub-Saharan African countries. In order to inform education and communication efforts to increase condom use, we examined social representations of condoms among young people aged 10-24 in six African countries/regions with diverse HIV prevalence rates: Swaziland, Namibia, Kenya, South-East Nigeria, Burkina Faso, and Senegal. We used a unique data source, namely 11,354 creative ideas contributed from these countries to a continent-wide scriptwriting contest, held from 1(st) February to 15(th) April 2005, on the theme of HIV/AIDS. We stratified each country sample by the sex, age (10-14, 15-19, 20-24), and urban/rural location of the author and randomly selected up to 10 narratives for each of the 12 resulting strata, netting a total sample of 586 texts for the six countries. We analyzed the narratives qualitatively using thematic data analysis and narrative-based methodologies. Differences were observed across settings in the prominence accorded to condoms, the assessment of their effectiveness, and certain barriers to and facilitators of their use. Moralization emerged as a key impediment to positive representations of condoms, while humour was an appealing means to normalize them. The social representations in the narratives identify communication needs in and across settings and provide youth-focused ideas and perspectives to inform future intervention efforts.

  7. [Maintenance of the relation between the pulsed secretion of hormones and the internal sleep structure in human African trypanosomiasis].

    PubMed

    Brandenberger, G; Buguet, A; Spiegel, K; Stanghellini, A; Mouanga, G; Bogui, P; Montmayeur, A; Dumas, M

    1994-01-01

    In order to determine whether sleep disturbances would affect the hormonal patterns and the normal relationships between hormone pulses and sleep stages, the 24-hour profiles of cortisol, prolactin and plasma renin activity (PRA) were analysed in 6 sleeping sickness patients studied at Brazzaville and in 5 healthy African controls studied in Abidjan. Polysomnographic recordings were done continuously and blood was taken every 10 minutes throughout the 24-hour period. Plasma was analyzed for cortisol, prolactin and PRA. The circadian rhythm of cortisol, considered as an example of an endogenous rhythm was attenuated in all the patients but one, but as in normal subjects, slow wave sleep (SWS) remained associated with the declining phases of the secretory episodes. Prolactin and PRA profiles, which are strongly influenced by the sleep-wake cycle did not show the increase normally associated with long sleep periods and reflected the spreading of sleep and wakefulness throughout the 24-hour period. However, rapid-eye movement (REM) sleep began in sleeping sickness patients, as in normal subjects, during the descending phases of prolactin pulses. In both groups, PRA reflected the sleep stage distribution with non rapid-eye movement (NREM) sleep occurring during the ascending phases and REM sleep during the descending phases of the oscillations. However, in sleeping sickness patients, the marked sleep fragmentation often did not allow sufficient time for PRA to increase significantly, as observed with regular NREM-REM sleep cycles. These results demonstrate that, together with the disruption of the sleep-wake cycle, there are profound differences in the temporal organization of the 24 hour hormone profiles in human African trypanosomiasis.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Evolutionary plasticity in coccidia - striking morphological similarity of unrelated coccidia (apicomplexa) from related hosts: Eimeria spp. from African and Asian Pangolins (Mammalia: Pholidota).

    PubMed

    Jirků, Miloslav; Kvičerová, Jana; Modrý, David; Hypša, Václav

    2013-07-01

    Two morphologically similar, but phylogenetically unrelated Eimeria species from ancient mammals, African Tree Pangolin Phataginus tricuspis and Sunda Pangolin Manis javanica (Pholidota: Manidae), from two distant biogeographic realms (Afrotropical and Oriental), are characterized and compared morphologically and molecularly. Phylogenetic analyses produced an unstable topology. However, while precise position of the two Eimeria species from pangolins could not be firmly established due to the lack of related taxa, it is evident that they are not closely related and do not fall into any of the so far recognized eimerian lineages. Moreover, an eimerian found in P. tricuspis is described as a new species Eimeria nkaka n. sp., based on morphology of oocysts, endogenous developmental stages and sequence data. PMID:23837921

  9. Evolutionary plasticity in coccidia - striking morphological similarity of unrelated coccidia (apicomplexa) from related hosts: Eimeria spp. from African and Asian Pangolins (Mammalia: Pholidota).

    PubMed

    Jirků, Miloslav; Kvičerová, Jana; Modrý, David; Hypša, Václav

    2013-07-01

    Two morphologically similar, but phylogenetically unrelated Eimeria species from ancient mammals, African Tree Pangolin Phataginus tricuspis and Sunda Pangolin Manis javanica (Pholidota: Manidae), from two distant biogeographic realms (Afrotropical and Oriental), are characterized and compared morphologically and molecularly. Phylogenetic analyses produced an unstable topology. However, while precise position of the two Eimeria species from pangolins could not be firmly established due to the lack of related taxa, it is evident that they are not closely related and do not fall into any of the so far recognized eimerian lineages. Moreover, an eimerian found in P. tricuspis is described as a new species Eimeria nkaka n. sp., based on morphology of oocysts, endogenous developmental stages and sequence data.

  10. Oncology pharmacy units: a safety policy for handling hazardous drugs and related waste in low- and middle-income African countries—Angolan experience

    PubMed Central

    da Conceição, Ana Vaz; Bernardo, Dora; Lopes, Lygia Vieira; Miguel, Fernando; Bessa, Fernanda; Monteiro, Fernando; Santos, Cristina; Oliveira, Blasques; Santos, Lúcio Lara

    2015-01-01

    In African countries, higher rates of late-stage cancers at the time of first diagnosis are a reality. In this context, hazardous drugs (HDs), such as chemotherapy, play an important role and have immense benefits for patients’ treatment. HDs should be handled under specific conditions. At least a class 5 environment primary engineering control (PEC), physically located in an appropriate buffer area, is mandatory for sterile HDs compounding, as well as administrative control, personal protective equipment, work practices and other engineering and environmental controls, in order to protect the environment, patient, and worker. The aim of this study is to describe the Angolan experience regarding the development of oncology pharmacy units and discuss international evidence-based guidelines on handling HDs and related waste. Measures to incorporate modern and economical solutions to upgrade or build adequate and safe facilities and staff training, in order to comply with international guidelines in this area, are crucial tasks for African countries of low and middle income. PMID:26557873

  11. The relative role of ocean-atmosphere interaction and African easterly waves in the generation and development of Tropical cyclones in the North Atlantic

    NASA Astrophysics Data System (ADS)

    Cabos, William; Sein, Dmitry; Hodges, Kevin; Jacob, Daniela

    2016-04-01

    We use the regionally coupled ocean - atmosphere model ROM and its atmospheric component REMO in standalone configuration in order to assess the relative role of ocean feedbacks and the African easterly waves in the simulation of tropical cyclonic activity in the Atlantic ocean. To this end, a number of coupled and uncoupled simulations forced by ERA-Interim boundary conditions have been carried out. In one set of simulations, the atmospheric domain includes the Northern Africa land masses, where the easterly waves are formed. In a second set of simulations, the easterly waves are taken from the ERA Interim reanalysis, as atmospheric domain excludes explicitly the African land masses. We study the statistics of modeled tracks of the tropical cyclones in the simulations. We found that the coupling has a strong impact on the number of tropical cyclones generated in the Northern Tropical Atlantic. In the coupled run it was close to the observations, while in the uncoupled runs the number of tropical cyclones was strongly overestimated. The coupling also influences the simulated position of the ITCZ.

  12. Preventing HIV among Latino and African American Gay and Bisexual Men in a Context of HIV-Related Stigma, Discrimination, and Homophobia: Perspectives of Providers

    PubMed Central

    Brooks, Ronald A.; Etzel, Mark A.; Hinojos, Ernesto; Henry, Charles L.; Perez, Mario

    2005-01-01

    HIV-related stigma, discrimination, and homophobia impede community based efforts to combat HIV disease among Latino and African American gay and bisexual men. This commentary highlights ways to address these social biases in communities of color in Los Angeles from the perspectives of staff from HIV prevention programs. Information was collected from HIV prevention program staff participating in a two-day symposium. The outcomes from the symposium offer strategies for developing and implementing HIV prevention services for Latino and African American gay and bisexual men, which include: 1) addressing social biases present in a community that can hinder, and even prohibit, utilization of effective HIV prevention programs; 2) recasting HIV prevention messages in a broader social or health context; 3) developing culturally appropriate HIV prevention messages; 4) exploring new modalities and venues for delivering HIV prevention messages that are appropriate for gay and bisexual men of color and the communities in which they live; and 5) broadening the target of HIV prevention services to include service providers, local institutions and agencies, and the community at-large. These strategies underscore the need to consider the social and contextual factors of a community when designing and implementing HIV prevention programs. PMID:16283834

  13. Molecular Variation of Adh and P6 Genes in an African Population of Drosophila Melanogaster and Its Relation to Chromosomal Inversions

    PubMed Central

    Benassi, V.; Aulard, S.; Mazeau, S.; Veuille, M.

    1993-01-01

    Four-cutter molecular polymorphism of Adh and P6, and chromosome inversion polymorphism of chromosome II were investigated in 95 isogenic lines of an Ivory Coast population of Drosophila melanogaster, a species assumed to have recently spread throughout the world from a West African origin. The P6 gene showed little linkage disequilibrium with the In(2L)t inversion, although it is located within this inversion. This suggests that the inversion and the P6 locus have extensively exchanged genetic information through either double crossover or gene conversion. Allozymic variation in ADH was in linkage disequilibrium with In(2L)t and In(2R)NS inversions. Evidence suggests either that inversion linkage with the Fast allele is selectively maintained, or that this allele only recently appeared. Molecular polymorphism at the Adh locus in the Ivory Coast is not higher than in North American populations. New haplotypes specific to the African population were found, some of them connect the ``Wa(s)-like'' haplotypes found at high frequencies in the United States to the other slow haplotypes. Their relation with In(2L)t supports the hypothesis that Wa(s) recently recombined away from an In(2L)t chromosome which may be the cause of its divergence from the other haplotypes. PMID:8349110

  14. Social support buffering of the relation between low income and elevated blood pressure in at-risk African-American adults.

    PubMed

    Coulon, S M; Wilson, D K

    2015-10-01

    Socioeconomic disadvantage has been linked to elevated blood pressure (BP), and the purpose of this study was to assess whether interpersonal social supports buffer these adverse relations in African-American adults. In three communities matched demographically, a subsample of participants (N = 204) of the Positive Action for Today's Health trial provided measures of perceived social support, annual household income, and BP. Multiple regression analyses with cross-product interactions were conducted using follow-up data. The sample had a mean age of 52.8 years (SD = 15.1), and was predominantly female (66 %) with a high body mass index (M = 33.5, SD = 14.7). Results indicated an inverse relation between social support and diastolic BP (B = -.178, p = .005), and also an interaction with income (p = .046), such that higher social support related to lower diastolic BP in the lowest-income individuals (B = -1.05). The same direct (B = -.141, p = .025) and interacting (B = -1.42, p = .040) social support effects were present for systolic BP, however the omnibus model for systolic BP was not significant, F(6, 196) = 1.80, p = .09. The hypothesized buffering effect of social support on the adverse relation of income to BP was partially supported in at-risk African-American adults. Future prevention efforts for reducing the impact of socioeconomic stress on BP may aim to increase perceptions of social support. PMID:26156119

  15. The effects of a mass media HIV-risk reduction strategy on HIV-related stigma and knowledge among African American adolescents.

    PubMed

    Kerr, Jelani C; Valois, Robert F; DiClemente, Ralph J; Carey, Michael P; Stanton, Bonita; Romer, Daniel; Fletcher, Faith; Farber, Naomi; Brown, Larry K; Vanable, Peter A; Salazar, Laura F; Juzang, Ivan; Fortune, Thierry

    2015-03-01

    HIV-related stigma undermines HIV prevention, testing, and treatment. Multipronged risk-reduction strategies may reduce stigma among African American adolescents. To test the effectiveness of a risk-reduction strategy in addressing stigma, 1613 African American adolescents from four mid-sized cities participated in a randomized control trial. Participants received a sexual-risk reduction [Focus on Youth (FOY)] or general health curriculum [Promoting Health Among Teens (PHAT)]. Two cities received a culturally-tailored media intervention. Participants completed baseline, 3-, 6-, and 12-month surveys to measure HIV-related stigma and knowledge. Analysis of covariance tested for stigma and knowledge differences by media city status and curriculum/media city status (PHAT media vs. PHAT non-media, FOY media vs. FOY non-media; FOY media vs. PHAT media; FOY non-media vs. PHAT non-media) at each measurement. Hierarchical linear modeling (HLM) determined stigma and knowledge differences over time. Media participants demonstrated greater HIV-related knowledge (p<0.10) at 6 months and lower stigma at 3 months (p<0.10). FOY media participants had lower 3-month (p<0.05) and 12-month (p<0.10) stigma scores than non-media FOY participants. FOY media and non-media participants had greater knowledge than PHAT for all intervals after baseline. FOY media had lower stigma than PHAT media after baseline for all intervals after baseline. HLM indicated greater knowledge slopes for the media group (p<0.05). FOY media participants had greater knowledge slopes (p<0.05) relative to non-media FOY participants and media PHAT participants (p<0.01). A combination of a HIV risk-reduction curriculum and culturally-tailored media demonstrated some effectiveness in reducing stigma. Future use of media in HIV-prevention should include and evaluate effects on stigma.

  16. The effects of a mass media HIV-risk reduction strategy on HIV-related stigma and knowledge among African American adolescents.

    PubMed

    Kerr, Jelani C; Valois, Robert F; DiClemente, Ralph J; Carey, Michael P; Stanton, Bonita; Romer, Daniel; Fletcher, Faith; Farber, Naomi; Brown, Larry K; Vanable, Peter A; Salazar, Laura F; Juzang, Ivan; Fortune, Thierry

    2015-03-01

    HIV-related stigma undermines HIV prevention, testing, and treatment. Multipronged risk-reduction strategies may reduce stigma among African American adolescents. To test the effectiveness of a risk-reduction strategy in addressing stigma, 1613 African American adolescents from four mid-sized cities participated in a randomized control trial. Participants received a sexual-risk reduction [Focus on Youth (FOY)] or general health curriculum [Promoting Health Among Teens (PHAT)]. Two cities received a culturally-tailored media intervention. Participants completed baseline, 3-, 6-, and 12-month surveys to measure HIV-related stigma and knowledge. Analysis of covariance tested for stigma and knowledge differences by media city status and curriculum/media city status (PHAT media vs. PHAT non-media, FOY media vs. FOY non-media; FOY media vs. PHAT media; FOY non-media vs. PHAT non-media) at each measurement. Hierarchical linear modeling (HLM) determined stigma and knowledge differences over time. Media participants demonstrated greater HIV-related knowledge (p<0.10) at 6 months and lower stigma at 3 months (p<0.10). FOY media participants had lower 3-month (p<0.05) and 12-month (p<0.10) stigma scores than non-media FOY participants. FOY media and non-media participants had greater knowledge than PHAT for all intervals after baseline. FOY media had lower stigma than PHAT media after baseline for all intervals after baseline. HLM indicated greater knowledge slopes for the media group (p<0.05). FOY media participants had greater knowledge slopes (p<0.05) relative to non-media FOY participants and media PHAT participants (p<0.01). A combination of a HIV risk-reduction curriculum and culturally-tailored media demonstrated some effectiveness in reducing stigma. Future use of media in HIV-prevention should include and evaluate effects on stigma. PMID:25738952

  17. Social support buffering of the relation between low income and elevated blood pressure in at-risk African-American adults.

    PubMed

    Coulon, S M; Wilson, D K

    2015-10-01

    Socioeconomic disadvantage has been linked to elevated blood pressure (BP), and the purpose of this study was to assess whether interpersonal social supports buffer these adverse relations in African-American adults. In three communities matched demographically, a subsample of participants (N = 204) of the Positive Action for Today's Health trial provided measures of perceived social support, annual household income, and BP. Multiple regression analyses with cross-product interactions were conducted using follow-up data. The sample had a mean age of 52.8 years (SD = 15.1), and was predominantly female (66 %) with a high body mass index (M = 33.5, SD = 14.7). Results indicated an inverse relation between social support and diastolic BP (B = -.178, p = .005), and also an interaction with income (p = .046), such that higher social support related to lower diastolic BP in the lowest-income individuals (B = -1.05). The same direct (B = -.141, p = .025) and interacting (B = -1.42, p = .040) social support effects were present for systolic BP, however the omnibus model for systolic BP was not significant, F(6, 196) = 1.80, p = .09. The hypothesized buffering effect of social support on the adverse relation of income to BP was partially supported in at-risk African-American adults. Future prevention efforts for reducing the impact of socioeconomic stress on BP may aim to increase perceptions of social support.

  18. Calculation of relative tube/tube support plate displacements in steam generators under accident condition loads using non-linear dynamic analysis methodologies

    SciTech Connect

    Smith, R.E.; Waisman, R.; Hu, M.H.; Frick, T.M.

    1995-12-01

    A non-linear analysis has been performed to determine relative motions between tubes and tube support plates (TSP) during a steam line break (SLB) event for steam generators. The SLB event results in blowdown of steam and water out of the steam generator. The fluid blowdown generates pressure drops across the TSPS, resulting in out-of-plane motion. The SLB induced pressure loads are calculated with a computer program that uses a drift-flux modeling of the two-phase flow. In order to determine the relative tube/TSP motions, a nonlinear dynamic time-history analysis is performed using a structural model that considers all of the significant component members relative to the tube support system. The dynamic response of the structure to the pressure loads is calculated using a special purpose computer program. This program links the various substructures at common degrees of freedom into a combined mass and stiffness matrix. The program accounts for structural non-linearities, including potential tube and TSP interaction at any given tube position. The program also accounts for structural damping as part of the dynamic response. Incorporating all of the above effects, the equations of motion are solved to give TSP displacements at the reduced set of DOF. Using the displacement results from the dynamic analysis, plate stresses are then calculated using the detailed component models. Displacements form the dynamic analysis are imposed as boundary conditions at the DOF locations, and the finite element program then solves for the overall distorted geometry. Calculations are also performed to assure that assumptions regarding elastic response of the various structural members and support points are valid.

  19. The African-American History of Martha's Vineyard.

    ERIC Educational Resources Information Center

    Weintraub, Elaine

    1993-01-01

    Reports on research into African American history and experiences in Martha's Vineyard (Massachusetts). Examines primary sources and oral traditions of African American cultural and social history from 1703 to the present. Discusses African American sailors, race relations, and contributions by African American individuals to the community. (CFR)

  20. “You’re losing your Ghanaianess”: understanding malaria decision-making among Africans visiting friends and relatives in the UK

    PubMed Central

    2014-01-01

    Background In the UK, the majority of imported malaria infections occur in the London area among UK residents of African origin who travel to Africa visiting friends and relatives (VFRs). Effective malaria prevention measures are available but there is little understanding of the factors that enhance and constrain their use among VFRs. Methods Semi-structured interviews were undertaken with Africans resident in London who visited friends and relatives in Nigeria and Ghana (n = 20) and with African VFRs recently treated for malaria (n = 6). Data collection took place between December 2007 and February 2011. Information on migration patterns and travel of respondents was collected and the data were analysed using a framework analysis approach. Results Knowledge of the link between mosquitoes and malaria was high. Factors influencing the use of mosquito avoidance methods included knowledge about the local environment, perceptions of the inevitability of contracting malaria, and a desire to fit with the norms of host families. Previous experience of bed nets, and the belief that more modern ways of preventing mosquito bites were available deterred people from using them. Chemoprophylaxis use was varied and influenced by: perceptions about continuing immunity to malaria; previous experiences of malaria illness; the cost of chemoprophylaxis; beliefs about the likely severity of malaria infections; the influence of friends in the UK; and, the way malaria is perceived and managed in Nigeria and Ghana. Malaria treatment was considered by many to be superior in Nigeria and Ghana than in the UK. A conceptual framework was developed to illustrate the manner in which these factors interact to affect malaria decisions. Conclusions The use of malaria prevention among VFRs needs to be understood not only in terms of individual risk factors but also in relation to the context in which decisions are made. For VFRs, malaria decisions are undertaken across two distinct social

  1. Localised Plate Motion on Venus

    NASA Astrophysics Data System (ADS)

    Ghail, R. C.

    1996-03-01

    The volcanic and tectonic features observed in Dali Vinculum, Parga Vinculum and Imdr Regio are concentrated at long, narrow, curvilinear zones, with relatively minor volcanism and tectonism between these zones. These zones, whilst more diffuse than terrestrial plate boundaries, nevertheless define the margins of tectonic plates. In contrast to Earth, however, it appears that venusian plates are neither created nor destroyed by lateral motion. Rather, plates are thinned and intruded at vincula plate boundaries, vertically accreted by small-scale intra-plate (planitia) volcanism and perhaps destroyed by delamination of thickened crust in tesserae and montane regions such as Thetis Regio and Ishtar Terra. The diversity in age both between and within these three areas together with the evidence for infrequent, small scale resurfacing in the planitiae are difficult to reconcile with a non-uniformitarian geological process.

  2. Genome-wide association study of a heart failure related metabolomic profile among African Americans in the Atherosclerosis Risk in Communities (ARIC) study.

    PubMed

    Yu, Bing; Zheng, Yan; Alexander, Danny; Manolio, Teri A; Alonso, Alvaro; Nettleton, Jennifer A; Boerwinkle, Eric

    2013-12-01

    Both the prevalence and incidence of heart failure (HF) are increasing, especially among African Americans, but no large-scale, genome-wide association study (GWAS) of HF-related metabolites has been reported. We sought to identify novel genetic variants that are associated with metabolites previously reported to relate to HF incidence. GWASs of three metabolites identified previously as risk factors for incident HF (pyroglutamine, dihydroxy docosatrienoic acid, and X-11787, being either hydroxy-leucine or hydroxy-isoleucine) were performed in 1,260 African Americans free of HF at the baseline examination of the Atherosclerosis Risk in Communities (ARIC) study. A significant association on chromosome 5q33 (rs10463316, MAF = 0.358, P-value = 1.92 × 10(-10) ) was identified for pyroglutamine. One region on chromosome 2p13 contained a nonsynonymous substitution in N-acetyltransferase 8 (NAT8) was associated with X-11787 (rs13538, MAF = 0.481, P-value = 1.71 × 10(-23) ). The smallest P-value for dihydroxy docosatrienoic acid was rs4006531 on chromosome 8q24 (MAF = 0.400, P-value = 6.98 × 10(-7) ). None of the above SNPs were individually associated with incident HF, but a genetic risk score (GRS) created by summing the most significant risk alleles from each metabolite detected 11% greater risk of HF per allele. In summary, we identified three loci associated with previously reported HF-related metabolites. Further use of metabolomics technology will facilitate replication of these findings in independent samples.

  3. The African and Pacific Superplume Structures Constrained by Assembly and Breakup of Pangea

    NASA Astrophysics Data System (ADS)

    Zhang, N.; Zhong, S.; Leng, W.; Li, Z.

    2009-12-01

    Seismic tomography studies indicate that the Earth’s mantle structure is characterized by African and Pacific seismically slow velocity anomalies (i.e., superplumes) and circum-Pacific seismically fast anomalies (i.e., a globally spherical harmonic degree-2 structure). McNamara and Zhong (2005) have demonstrated that the African and Pacific superplume structures result from dynamic interaction between mantle convection and surface plate motion history in the last 120 Ma. However, their models produce slightly stronger degree 3 structure than degree 2 near the CMB. Here, we construct a proxy model of plate motions for the African hemisphere for the last 450 Ma since the Early Paleozoic using the paleogeographic reconstruction of continents constrained by paleomagnetic and geological observations. Using this proxy model for plate motion history as the time-dependent surface boundary conditions for a 3-dimensional spherical model of thermochemical mantle convection, we calculate the present-day mantle structure and explore the evolution of mantle structures since the Early Paleozoic. Our model calculations reproduce well the present-day mantle structure including the African and Pacific superplumes. The power spectra of our calculated present-day temperature field shows that the strongest power occurs at degree 2 in the lower mantle while in the upper mantle the strongest power is at degree 3. The degree correlation between tomography model S20RTS and our calculated temperature field shows a high correlation at the degree 1 and degree 2 in the lower mantle while the upper mantle and the short wavelength structures do not correlate well. The summed degree correlation for the lower mantle shows a relatively good correlation for the bottom 300 km of the mantle but the correlation is significantly reduced at depth 600 km above the CMB. For the evolution of mantle structures, we focus on the evolution of the African superplume. Our results suggest that the mantle in the

  4. Dynamics and stress field of the Eurasian plate

    NASA Astrophysics Data System (ADS)

    Warners-Ruckstuhl, Karin; Govers, Rob; Wortel, Rinus

    2013-04-01

    extent, to lithospheric density structure and normal pressure from mantle flow. Stress observations require collision forces on the India-Eurasia boundary of 7.2 - 10.5 T N/m and on the Arabia-Eurasia boundary of 1.3 - 2.3 T N/m. Implication of mechanical equilibrium of the plate is that forces on the contacts with the African and Australian plates amount to 1.0 - 2.1 and 0 - 0.8 T N/m, respectively. The inferred collision forces are part of the best-fitting overall set of forces acting on the Eurasian plate, satisfying constraints from basic mechanics, absolute plate motion and stress field. We use our results to assess the validity of the classical view that the mean elevation of an orogenic plateau can be taken as a measure of the magnitude of the compressive (in this case: collision-related) forces involved. We find that for both the Tibetan and the Iranian plateau, two plateaus with significantly different average elevations, the horizontal force derived from the excess gravitational potential energy (collapse force) is in balance with the collision force, thus confirming the hypothesis of balanced topography.

  5. Generating Conflict for Greater Good: Utilizing Contingency Theory to Assess Black and Mainstream Newspapers as Public Relations Vehicles to Promote Better Health among African Americans.

    PubMed

    Lumpkins, Crystal Y; Bae, Jiyang; Cameron, Glen T

    2010-03-01

    The potential use of strategic conflict management ( Wilcox and Cameron, 2006; Cameron, Wilcox, Reber and Shin ( in press) as a health advocacy tool in US African-American and mainstream newspapers, arguing that escalation of conflict can increase effectiveness of health-related news releases. For health communicators focusing on at-risk populations with poor health outcomes, such goals would include increased awareness of health problems and solutions, along with increased motivation arising from indignation over health disparities. Content analysis of 1,197 stories in 24 Black and 12 mainstream newspapers showed that more conflict factors were present in Black vs. mainstream newspapers, suggesting a way to strategically place health messages in news releases disseminated to newspapers that motivate at-risk publics to better health. The findings suggest that conflict factors such as racial disparity data regarding health issues may enhance media advocacy.

  6. Pro-opiomelanocortin (POMC) expression and immunolocalization of POMC-related peptides in the ovary of Protopterus annectens, an African lungfish.

    PubMed

    Masini, M A; Sturla, M; Pestarino, M; Gallinelli, A; Facchinetti, F; Uva, B M

    1997-01-01

    Antisera against adrenocorticotropic hormone (ACTH), alpha-melanocyte-stimulating hormone (alpha MSH) and beta-endorphin were used to localize pro-opiomelanocortin (POMC)-derived peptides in the ovary of the African lungfish Protopterus annectens by immunohistochemistry. Immunoreactivity was observed in the granulosa and the internal theca of the vitellogenic follicles. No immunoreactivity was observed in immature follicles. Using human POMC cDNA as the hybridization probe POMC-like mRNA was identified in situ in cells of the granulosa and internal theca of the vitellogenic follicles. No labeling was observed in primordial follicles. The demonstration in the same cells of POMC mRNA and POMC-related peptides immunoreactivity indicates a local production of the opiate hormones.

  7. Generating Conflict for Greater Good: Utilizing Contingency Theory to Assess Black and Mainstream Newspapers as Public Relations Vehicles to Promote Better Health among African Americans

    PubMed Central

    Lumpkins, Crystal Y.; Bae, Jiyang; Cameron, Glen T.

    2010-01-01

    The potential use of strategic conflict management ( Wilcox and Cameron, 2006; Cameron, Wilcox, Reber and Shin ( in press) as a health advocacy tool in US African-American and mainstream newspapers, arguing that escalation of conflict can increase effectiveness of health-related news releases. For health communicators focusing on at-risk populations with poor health outcomes, such goals would include increased awareness of health problems and solutions, along with increased motivation arising from indignation over health disparities. Content analysis of 1,197 stories in 24 Black and 12 mainstream newspapers showed that more conflict factors were present in Black vs. mainstream newspapers, suggesting a way to strategically place health messages in news releases disseminated to newspapers that motivate at-risk publics to better health. The findings suggest that conflict factors such as racial disparity data regarding health issues may enhance media advocacy. PMID:22822291

  8. Generating Conflict for Greater Good: Utilizing Contingency Theory to Assess Black and Mainstream Newspapers as Public Relations Vehicles to Promote Better Health among African Americans.

    PubMed

    Lumpkins, Crystal Y; Bae, Jiyang; Cameron, Glen T

    2010-03-01

    The potential use of strategic conflict management ( Wilcox and Cameron, 2006; Cameron, Wilcox, Reber and Shin ( in press) as a health advocacy tool in US African-American and mainstream newspapers, arguing that escalation of conflict can increase effectiveness of health-related news releases. For health communicators focusing on at-risk populations with poor health outcomes, such goals would include increased awareness of health problems and solutions, along with increased motivation arising from indignation over health disparities. Content analysis of 1,197 stories in 24 Black and 12 mainstream newspapers showed that more conflict factors were present in Black vs. mainstream newspapers, suggesting a way to strategically place health messages in news releases disseminated to newspapers that motivate at-risk publics to better health. The findings suggest that conflict factors such as racial disparity data regarding health issues may enhance media advocacy. PMID:22822291

  9. Distribution of physical properties and timing of relative uplift in upper plate off Costa Rica: IODP Expedition 344

    NASA Astrophysics Data System (ADS)

    Saiki, A.; Hashimoto, Y.

    2015-12-01

    Evolution of physical properties in subduction zone is a key to understand lithification processes, location of decollement, and stress distribution. In this study, we examined the physical properties of sediments using on-board data and laboratory experimental data on sediments obtained off Costa Rica margin. Target sites are in the Integrate Ocean Drilling Program (IODP) Expedition 344 off Costa Rica, including reference sites (U1381 and U1414), mid-slope site (U1378, U1380) and upper-slope site (U1413). Seven samples from reference sites were analyzed. Laboratory experiments for velocity and porosity measurements were conducted with variation of effective pressure. Velocity-porosity relationships from on-board data and from laboratory experiments are comparable. The porosity-effective pressure curves under isotropic condition were converted to the curves under uniaxial condition (Teeuw, 1971). Using the normal consolidation curves under uniaxial stress conditions, we converted onboard porosity to effective pressure and fluid pressure. In reference sites, hydrostatic fluid pressure was estimated as expected as a reference sites, suggesting that porosity-effective pressure relationship was obtained correctly by experiments and it can be adapted to estimation of fluid pressure for the wedge sites. The porosity-effective pressure relationship under isotropic conditions were used for the estimation in wedge sites. In wedge sites, estimated pore pressures show lower than hydrostatic pressure, suggesting that onboard porosity was lower than that under normal compaction. The lower porosity can be caused by relative uplift from deeper portion. The amount of relative uplift can be estimated by differences in porosity-depth relationships between onboard data and experimental data. The amount of relative uplift for each site shows more than ~1000m up to ~5000m. The small error in porosity depth curve from experimental data makes relative uplift larger or smaller

  10. Host acceptance, suitability, and effects of host deprivation on the West African egg parasitoid Telenomus isis (Hymenoptera: Scelionidae) reared on East African stemborers under varying temperature and relative humidity regimens.

    PubMed

    Bruce, Anani Yaovi; Schulthess, Fritz; Mueke, Jones

    2009-06-01

    Scelionid egg parasitoids of Telenomus spp. have been shown to significantly affect noctuid stemborer populations and yields of maize in western Africa. One of them, T. isis, has never been reported from eastern Africa and was introduced into the laboratories of the International Centre of Insect Physiology and Ecology, Kenya. This study evaluates the biotic potential of T. isis using East African stemborers as hosts. Host acceptance was tested using 15 lepidopteran borer species. Only noctuid stemborers were accepted for oviposition by T. isis. Sesamia calamistis Hampson, Sesamia nonagrioides (Lefebvre), and Busseola fusca (Fuller) were further used to study the effect of host species, host age, duration of host deprivation, temperature, and humidity on the performance of the parasitoid. In contrast to sex ratio, developmental time, parasitism, and parasitoid emergence varied significantly with host species, and the former two decreased with the age of host eggs. Female longevity increased with duration of host deprivation, whereas average lifetime fecundity decreased, probably because of oocyte resorption. T. isis successfully developed between 18 and 32 degrees C at both low (40-50%) and high (70-80%) relative humidity regimens, but temperature played a more critical role. Using the modified Logan model, the lower and upper temperature thresholds for development were estimated at 11.5 and 37.5 degrees C, respectively, with an optimum at 30.5 degrees C for both humidity regimens. Depending on temperature and relative humidity regimen, the intrinsic rate of increase (r(m)) varied from 0.077 to 0.300, net reproductive rate (R(o)) from 7.70 to 83.96, and generation time (G) from 11 to 38 d. The results of this study indicate that T. isis is likely to establish in eastern Africa.

  11. Nappes, tectonics of oblique plate convergence, and metamorphic evolution related to 140 million years of continuous subduction, Franciscan Complex, California

    SciTech Connect

    Wakabayashi, J. )

    1992-01-01

    This paper presents a new synthesis of Franciscan Complex tectonics, with the emphasis on the pre-San Andreas fault history of these rocks. Field relations suggest that the Franciscan is characterized by nappe structures that formed during sequential accretion at the trench. The presence of these structures along with other field relations, including the lack of evidence for large offset of conglomerate suites, indicates that strike-slip fault systems of large displacement ({gt}500 km) did not cut the Franciscan Complex during subduction. Regional geology and comparisons to modern arc-trench systems suggest that strike-slip faulting associated with oblique subduction took place inboard (east) of the Franciscan in the vicinity of the magmatic arc. The Franciscan varies along strike, because individual accreted elements (packets of trench sediment, seamounts, etc.) did not extend the full length of the trench. Different depths of underplating, distribution of post-metamorphic faulting, and level of erosion produced the present-day surface distribution of high P/T metamorphism. Franciscan Complex tectonic history is presented in this paper.

  12. "My hair or my health:" Overcoming barriers to physical activity in African American women with a focus on hairstyle-related factors.

    PubMed

    Huebschmann, Amy G; Campbell, Lucille Johnson; Brown, Candace S; Dunn, Andrea L

    2016-01-01

    Physical activity disparities among African American (AA) women may be related to sociocultural barriers, including difficulties with restyling hair after exercise. We sought to identify physical activity barriers and facilitators in AA women with a focus on sociocultural factors related to hairstyle maintenance. Participants (n = 51) were AA women aged 19-73 years who completed valid surveys and participated in structured focus groups, stratified by age and physical activity levels, from November 2012 to February 2013. The Constant Comparison method was used to develop qualitative themes for barriers and facilitators. The most frequently reported general physical activity barrier among exercisers was "lack of money" (27%) and among non-exercisers was "lack of self-discipline" (57%). A hairstyle-related barrier of "sweating out my hairstyle" was reported by 7% of exercisers and 29% of non-exercisers. This hairstyle-related barrier included the need for extra time and money to restyle hair due to perspiration. Hairstyle-related facilitators included: prioritizing health over hairstyle and high self-efficacy to restyle hair after perspiration. Participants were interested in resources to simplify hairstyle maintenance. AA women whose hairstyle is affected by perspiration may avoid physical activity due to time and financial burdens. Increasing self-efficacy to restyle hair after perspiration may help to overcome this barrier.

  13. African Aesthetics

    ERIC Educational Resources Information Center

    Abiodun, Rowland

    2001-01-01

    No single traditional discipline can adequately supply answers to the many unresolved questions in African art history. Because of the aesthetic, cultural, historical, and, not infrequently, political biases, already built into the conception and development of Western art history, the discipline of art history as defined and practiced in the West…

  14. "African Connection."

    ERIC Educational Resources Information Center

    Adelman, Cathy; And Others

    This interdisciplinary unit provides students in grades kindergarten through seventh grade an opportunity to understand diversity through a study of Africa as a diverse continent. The project is designed to provide all elementary students with cultural enrichment by exposing them to African music, art, storytelling, and movement. This project can…

  15. Expression of cell adhesion and differentiation related genes in MC3T3 osteoblasts plated on titanium alloys: role of surface properties.

    PubMed

    Sista, Subhash; Wen, Cuie; Hodgson, Peter D; Pande, Gopal

    2013-04-01

    It is important to understand the cellular and molecular events that take place at the cell-material interface of implants used for bone repair. An understanding of the mechanisms involved in the initial stages of osteoblast interactions with the surface of the implant material is fundamental in deciding the fate of the cells that come in contact with it. In this study, we compared the relative gene expression of markers that are known to be associated with cell adhesion and differentiation in MC3T3 osteoblast cells, at various time points after plating the cells on surfaces of titanium (Ti) and its two alloys, titanium-zirconium (TiZr) and titanium-niobium (TiNb) by using Quantitative Real Time Polymerase Chain Reaction (RT-PCR). Our analysis indicated that expression of adhesion supporting genes was higher on TiZr surface as compared to Ti and TiNb. The behavior of these genes is possibly driven by a higher surface energy of TiZr. However no significant difference in the expression of differentiation related genes could be seen between the two alloys, although on both substrates it was higher as compared to unalloyed Ti. We propose that substrate composition of the alloys can influence the adhesion and differentiation related gene expression and that Ti alloys are better substrates for inducing osteogenesis as compared to unalloyed Ti.

  16. The erosive effects of racism: reduced self-control mediates the relation between perceived racial discrimination and substance use in African American adolescents.

    PubMed

    Gibbons, Frederick X; O'Hara, Ross E; Stock, Michelle L; Gerrard, Meg; Weng, Chih-Yuan; Wills, Thomas A

    2012-05-01

    Perceived racial discrimination, self-control, anger, and either substance use or use cognitions were assessed in 2 studies conducted with samples of African American adolescents. The primary goal was to examine the relation between discrimination and self-control over time; a 2nd goal was to determine whether that relation mediates the link between discrimination and substance use found in previous research. Study 1, which included a latent growth curve analysis with 3 waves of data, indicated that experience with discrimination (from age 10 years to age 18 years) was associated with reduced self-control, which then predicted increased substance use. Additional analyses indicated anger was also a mediator of this discrimination to use relation. Study 2, which was experimental, showed that envisioning an experience involving discrimination was associated with an increase in substance-related responses to double entendre words (e.g., pot, roach) in a word association task, especially for participants who were low in dispositional self-control. The effect was again mediated by reports of anger. Thus, the "double mediation" pattern was discrimination → more anger and reduced self-control → increased substance use and/or substance cognitions. Results are discussed in terms of the long-term impact of discrimination on self-control and health behavior. Implications for interventions aimed at ameliorating the negative effects of discrimination and low self-control on health are also discussed.

  17. Early initiation of sex, drug-related risk behaviors, and sensation-seeking among urban, low-income African-American adolescents.

    PubMed Central

    Stanton, B.; Li, X.; Cottrell, L.; Kaljee, L.

    2001-01-01

    The purpose of this study was to examine the relationship of early initiation of sex, drug-use, drug-trafficking, and sensation-seeking among urban, African-American adolescents. A longitudinal follow-up of 383 youth ages 9 to 15 years at baseline over four years with serial risk-assessments was used. Sexual experience and several drug-related risk behaviors increased significantly during the four-year study interval. Sensation-seeking scores were higher after the baseline assessment among youth reporting tobacco, alcohol, and marijuana use and were higher, both at baseline and through several follow-up assessments, among youth reporting drug-selling and sexual activity. At baseline, the correlations among drug-related risk behaviors were all strong, except those between initiation of sex and drug-related risk behaviors. However, over time, early initiators of sex were significantly more likely to report involvement in substance use and drug-delivery/sales than were late initiators. Youth reporting repeated involvement in drug-related activities were more likely to report intensive sexual involvement than they were to report experimental sex or no sex. Sensation-seeking scores were lower among youth reporting no involvement in risk behaviors. However, scores did not differ between youth exhibiting experimental behavior compared to youth demonstrating repeated risk involvement. These results support the need for alternative experiences for youth exhibiting high levels of sensation-seeking and the need for early drug/sexual risk prevention programs. PMID:12653400

  18. Early initiation of sex, drug-related risk behaviors, and sensation-seeking among urban, low-income African-American adolescents.

    PubMed

    Stanton, B; Li, X; Cottrell, L; Kaljee, L

    2001-04-01

    The purpose of this study was to examine the relationship of early initiation of sex, drug-use, drug-trafficking, and sensation-seeking among urban, African-American adolescents. A longitudinal follow-up of 383 youth ages 9 to 15 years at baseline over four years with serial risk-assessments was used. Sexual experience and several drug-related risk behaviors increased significantly during the four-year study interval. Sensation-seeking scores were higher after the baseline assessment among youth reporting tobacco, alcohol, and marijuana use and were higher, both at baseline and through several follow-up assessments, among youth reporting drug-selling and sexual activity. At baseline, the correlations among drug-related risk behaviors were all strong, except those between initiation of sex and drug-related risk behaviors. However, over time, early initiators of sex were significantly more likely to report involvement in substance use and drug-delivery/sales than were late initiators. Youth reporting repeated involvement in drug-related activities were more likely to report intensive sexual involvement than they were to report experimental sex or no sex. Sensation-seeking scores were lower among youth reporting no involvement in risk behaviors. However, scores did not differ between youth exhibiting experimental behavior compared to youth demonstrating repeated risk involvement. These results support the need for alternative experiences for youth exhibiting high levels of sensation-seeking and the need for early drug/sexual risk prevention programs. PMID:12653400

  19. The Erosive Effects of Racism: Reduced Self-control Mediates the Relation between Perceived Racial Discrimination and Substance Use in African American Adolescents

    PubMed Central

    Gibbons, Frederick X.; O'Hara, Ross E.; Stock, Michelle L.; Gerrard, Meg; Weng, Chih-Yuan; Wills, Thomas A.

    2012-01-01

    Perceived racial discrimination, self-control, anger, and either substance use or use cognitions were assessed in two studies conducted with samples of African American adolescents. The primary goal was to examine the relation between discrimination and self-control over time; a second goal was to determine if that relation mediates the link between discrimination and substance use found in previous research. Study 1, which included a latent growth curve analysis with three waves of data, indicated that experience with discrimination (from age 10 to age 18) was associated with reduced self-control, which then predicted increased substance use. Additional analyses indicated anger was also a mediator of this discrimination to use relation. Study 2, which was experimental, showed that envisioning an experience involving discrimination was associated with an increase in substance-related responses to double entendre words (e.g., “pot,” “roach”) in a word association task, especially for participants who were low in dispositional self-control. The effect was again mediated by reports of anger. Thus, the “double mediation” pattern was: discrimination → more anger and reduced self-control → increased substance use and/or substance cognitions. Results are discussed in terms of the long-term impact of discrimination on self-control and health behavior. Implications for interventions aimed at ameliorating the negative effects of discrimination and low self-control on health are also discussed. PMID:22390225

  20. An exome-wide analysis of low frequency and rare variants in relation to risk of breast cancer in African American Women: the AMBER Consortium.

    PubMed

    Haddad, Stephen A; Ruiz-Narváez, Edward A; Haiman, Christopher A; Sucheston-Campbell, Lara E; Bensen, Jeannette T; Zhu, Qianqian; Liu, Song; Yao, Song; Bandera, Elisa V; Rosenberg, Lynn; Olshan, Andrew F; Ambrosone, Christine B; Palmer, Julie R; Lunetta, Kathryn L

    2016-09-01

    A large percentage of breast cancer heritability remains unaccounted for, and most of the known susceptibility loci have been established in European and Asian populations. Rare variants may contribute to the unexplained heritability of this disease, including in women of African ancestry (AA). We conducted an exome-wide analysis of rare variants in relation to risk of overall and subtype-specific breast cancer in the African American Breast Cancer Epidemiology and Risk (AMBER) Consortium, which includes data from four large studies of AA women. Genotyping on the Illumina Human Exome Beadchip yielded data for 170 812 SNPs and 8287 subjects: 3629 cases (1093 estrogen receptor negative (ER-), 1968 ER+, 568 ER unknown) and 4658 controls, the largest exome chip study to date for AA breast cancer. Pooled gene-based association analyses were performed using the unified optimal sequence kernel association test (SKAT-O) for variants with minor allele frequency (MAF) ≤ 5%. In addition, each variant with MAF >0.5% was tested for association using logistic regression. There were no significant associations with overall breast cancer. However, a novel gene, FBXL22 (P = 8.2×10(-6)), and a gene previously identified in GWAS of European ancestry populations, PDE4D (P = 1.2×10(-6)), were significantly associated with ER- breast cancer after correction for multiple testing. Cases with the associated rare variants were also negative for progesterone and human epidermal growth factor receptors-thus, triple-negative cancer. Replication is required to confirm these gene-level associations, which are based on very small counts at extremely rare SNPs. PMID:27267999

  1. The relative contribution of viral and bacterial sexually transmitted infections on HIV acquisition in southern African women in the Methods for Improving Reproductive Health in Africa study.

    PubMed

    Venkatesh, K K; van der Straten, A; Cheng, H; Montgomery, E T; Lurie, M N; Chipato, T; Ramjee, G; Blanchard, K; Padian, N S; Mayer, K H; de Bruyn, G

    2011-04-01

    We assess the relative contribution of viral and bacterial sexually transmitted infections (STIs) on HIV acquisition among southern African women in a nested case-control study within the Methods for Improving Reproductive Health in Africa (MIRA) trial. Cases were women with incident HIV infection; controls were HIV-uninfected at the time of case seroconversion selected in a 1 to 3 case to control ratio (risk-set sampling), matched on study site and time of follow-up. Conditional logistic regression models were used to calculate adjusted odds ratios (AORs) and population-attributable fractions (PAF). Among 4948 enrolled women, we analysed 309 cases and 927 controls. The overall HIV incidence rate was 4.0 per 100 women-years. The incidence of HIV infection was markedly higher in women who had prevalent Herpes simplex virus type 2 (HSV-2) (AOR: 2.14; 95% confidence interval [CI]: 1.55-2.96), incident HSV-2 (AOR: 4.43; 95% CI: 1.77-11.05) and incident Neisseria gonorrhoeae (AOR: 6.92; 95% CI: 3.01-15.90). The adjusted PAF of HIV incidence for prevalent HSV-2 was 29.0% (95% CI: 16.8-39.3), for incident HSV-2 2.1% (95% CI: 0.6-3.6) and for incident N. gonorrhoeae 4.1% (95% CI: 2.5-5.8). Women's greatest risk factors for HIV acquisition were incident bacterial and viral STIs. Women-centred interventions aimed at decreasing HIV incidence in young African women need to address these common co-morbid conditions. PMID:21515755

  2. Tackle-related injury rates and nature of injuries in South African Youth Week tournament rugby union players (under-13 to under-18): an observational cohort study

    PubMed Central

    Burger, Nicholas; Lambert, Mike I; Viljoen, Wayne; Brown, James C; Readhead, Clint; Hendricks, Sharief

    2014-01-01

    Objectives The tackle situation is most often associated with the high injury rates in rugby union. Tackle injury epidemiology in rugby union has previously been focused on senior cohorts but less is known about younger cohorts. The aim of this study was to report on the nature and rates of tackle-related injuries in South African youth rugby union players representing their provinces at national tournaments. Design Observational cohort study. Setting Four South African Youth Week tournaments (under-13 Craven Week, under-16 Grant Khomo Week, under-18 Academy Week, under-18 Craven Week). Participants Injury data were collected from 3652 youth rugby union players (population at risk) in 2011 and 2012. Outcome measures Tackle-related injury severity (‘time-loss’ and ‘medical attention’), type and location, injury rate per 1000 h (including 95% CIs). Injury rate ratios (IRR) were calculated and modelled using a Poisson regression. A χ2 analysis was used to detect linear trends between injuries and increasing match quarters. Results The 2012 under-13 Craven Week had a significantly greater ‘time-loss’ injury rate when compared with the 2012 under-18 Academy Week (IRR=4.43; 95% CI 2.13 to 9.21, p<0.05) and under-18 Craven Week (IRR=3.52; 95% CI 1.54 to 8.00, p<0.05). The Poisson regression also revealed a higher probability of ‘overall’ (‘time-loss’ and ‘medical attention’ combined) and ‘time-loss’ tackle-related injuries occurring at the under-13 Craven Week. The proportion of ‘overall’ and ‘time-loss’ injuries increased significantly with each quarter of the match when all four tournaments were combined (p<0.05). Conclusions There was a difference in the tackle-related injury rate between the under-13 tournament and the two under-18 tournaments, and the tackle-related injury rate was higher in the final quarter of matches. Ongoing injury surveillance is required to better interpret these findings. Injury prevention strategies

  3. A Descriptive Qualitative Study Exploring Teacher and Parental Perceptions of African-American Middle School Male Students Related to Mathematics Performance

    ERIC Educational Resources Information Center

    Fowler, Crystal Nicole

    2013-01-01

    This qualitative descriptive case study explored the perceptions of parents and teachers of the academic achievement gap in mathematics between African-American middle school males and their White counterparts. Ten parents, both African-American and White, with students attending middle school in the Cherokee County School District and 5 teachers…

  4. Intervention Induced Changes on Parenting Practices, Youth Self-Pride and Sexual Norms to Reduce HIV-Related Behaviors among Rural African American Youths

    ERIC Educational Resources Information Center

    Murry, Velma McBride; Berkel, Cady; Chen, Yi-fu; Brody, Gene H.; Gibbons, Frederick X.; Gerrard, Meg

    2011-01-01

    AIDS is the leading killer of African Americans between the ages of 25 and 44, many of whom became infected when they were teenagers or young adults. The disparity in HIV infection rate among African Americans youth residing in rural Southern regions of the United States suggests that there is an urgent need to identify ways to promote early…

  5. HIV/AIDS prevention, faith, and spirituality among black/African American and Latino communities in the United States: strengthening scientific faith-based efforts to shift the course of the epidemic and reduce HIV-related health disparities.

    PubMed

    Sutton, Madeline Y; Parks, Carolyn P

    2013-06-01

    Black/African American and Latino communities are disproportionately affected by the domestic HIV/AIDS epidemic. Blacks/African Americans and Latinos are also more likely to report a formal, religious, or faith affiliation when compared with non-Hispanic whites. As such, faith leaders and their institutions have been identified in the National HIV/AIDS Strategy as having a vital role to serve in reducing: (1) HIV-related health disparities and (2) the number of new HIV infections by promoting non-judgmental support for persons living with and at risk for HIV/AIDS and by serving as trusted information resources for their congregants and communities. We describe faith doctrines and faith-science partnerships that are increasing in support of faith-based HIV prevention and service delivery activities and discuss the vital role of these faith-based efforts in highly affected black/African American and Latino communities.

  6. Emotion-Oriented Coping, Avoidance Coping, and Fear of Pain as Mediators of the Relationship between Positive Affect, Negative Affect, and Pain-Related Distress among African American and Caucasian College Women

    ERIC Educational Resources Information Center

    Lightsey, Owen Richard, Jr.; Wells, Anita G.; Wang, Mei-Chuan; Pietruszka, Todd; Ciftci, Ayse; Stancil, Brett

    2009-01-01

    The authors tested whether coping styles and fear of pain mediate the relationship between positive affect and negative affect on one hand and pain-related distress (PD) on the other. Among African American and Caucasian female college students, negative affect, fear of pain, and emotion-oriented coping together accounted for 34% of the variance…

  7. Bioethics training programmes for Africa: evaluating professional and bioethics-related achievements of African trainees after a decade of Fogarty NIH investment

    PubMed Central

    Kass, Nancy E; Ali, Joseph; Hallez, Kristina

    2016-01-01

    Objectives Our primary aim was to evaluate the impact of US National Institutes of Health (NIH)-funded bioethics training programmes (Fogarty bioethics training programmes, FBTPs) that trained individuals from Africa over the programme's first 10 years to examine changes between pretraining and post-training in individual achievement and to document any associations between individual, training programme and post-training accomplishments. Design We surveyed trainees from the 10 bioethics programmes funded by NIH Fogarty International Center from 2000 to 2011 that included African trainees. McNemar's and Wilcoxon signed rank-sum tests were used to analyse pre–post levels of general and bioethics-related professional achievement. Likelihood of specific post-training achievement outcomes was measured using logistic regression including demographic, pretraining and intratraining variables. Setting 10 different FBTPs that trained individuals from Africa from 2000 to 2011. Participants Of 253 eligible respondents, 171 completed the survey (response rate 67.6%). Primary outcome measures Pre–post comparisons of professional achievement indicators (eg, serving in leadership roles, teaching, publishing manuscripts); likelihood of specific post-training achievement outcomes. Results Post-training, respondents were significantly more likely to report serving in a leadership role, being an investigator on a research grant, serving on international committees, serving as a mentor, and publishing manuscripts than at pretraining. Post-training, significantly greater numbers of respondents reported bioethics-related achievements including being a bioethics instructor, serving on an Institutional Review Board (IRB), being an investigator on a bioethics grant and publishing bioethics-related manuscripts than pretraining. Controlling for other factors, there were no significant differences by gender in the post-training success of these participants in terms of leadership roles

  8. Associations between HIV-related stigma, racial discrimination, gender discrimination, and depression among HIV-positive African, Caribbean, and Black women in Ontario, Canada.

    PubMed

    Logie, Carmen; James, Llana; Tharao, Wangari; Loutfy, Mona

    2013-02-01

    Abstract African, Caribbean, and Black (ACB) women are greatly overrepresented in new HIV infections in comparison with Canada's general population. Social and structural factors such as HIV-related stigma, gender discrimination, and racial discrimination converge to increase vulnerability to HIV infection among ACB women by reducing access to HIV prevention services. Stigma and discrimination also present barriers to treatment, care, and support and may contribute to mental health problems. We administered a cross-sectional survey to HIV-positive ACB women (n=173) across Ontario in order to examine the relationships between HIV-related stigma, gender discrimination, racial discrimination, and depression. One-third of participants reported moderate/severe depression scores using the Beck Depression Inventory Fast-Screen guidelines. Hierarchical block regression, moderation, and mediation analyses were conducted to measure associations between independent (HIV-related stigma, gender discrimination, racial discrimination), moderator/mediator (social support, resilient coping), and dependent (depression) variables. Findings included: (1) HIV-related stigma was associated with increased depression; (2) resilient coping was associated with reduced depression but did not moderate the influence of HIV-related stigma on depression; and (3) the effects of HIV-related stigma on depression were partially mediated through resilient coping. HIV-related stigma, gender discrimination, and racial discrimination were significantly correlated with one another and with depression, highlighting the salience of examining multiple intersecting forms of stigma. Generalizability of findings may be limited due to nonrandom sampling. Findings emphasize the importance of multi-component interventions, including building resilient coping skills, mental health promotion and assessment, and stigma reduction programs.

  9. A new velocity field for Africa from combined GPS and DORIS space geodetic Solutions: Contribution to the definition of the African reference frame (AFREF)

    NASA Astrophysics Data System (ADS)

    Saria, E.; Calais, E.; Altamimi, Z.; Willis, P.; Farah, H.

    2013-04-01

    We analyzed 16 years of GPS and 17 years of Doppler orbitography and radiopositioning integrated by satellite (DORIS) data at continuously operating geodetic sites in Africa and surroundings to describe the present-day kinematics of the Nubian and Somalian plates and constrain relative motions across the East African Rift. The resulting velocity field describes horizontal and vertical motion at 133 GPS sites and 9 DORIS sites. Horizontal velocities at sites located on stable Nubia fit a single plate model with a weighted root mean square residual of 0.6 mm/yr (maximum residual 1 mm/yr), an upper bound for plate-wide motions and for regional-scale deformation in the seismically active southern Africa and Cameroon volcanic line. We confirm significant southward motion ( ˜ 1.5 mm/yr) in Morocco with respect to Nubia, consistent with earlier findings. We propose an updated angular velocity for the divergence between Nubia and Somalia, which provides the kinematic boundary conditions to rifting in East Africa. We update a plate motion model for the East African Rift and revise the counterclockwise rotation of the Victoria plate and clockwise rotation of the Rovuma plate with respect to Nubia. Vertical velocities range from - 2 to +2 mm/yr, close to their uncertainties, with no clear geographic pattern. This study provides the first continent-wide position/velocity solution for Africa, expressed in International Terrestrial Reference Frame (ITRF2008), a contribution to the upcoming African Reference Frame (AFREF). Except for a few regions, the African continent remains largely under-sampled by continuous space geodetic data. Efforts are needed to augment the geodetic infrastructure and openly share existing data sets so that the objectives of AFREF can be fully reached.

  10. Recent plate motions and crustal deformation

    SciTech Connect

    Lisowski, M. )

    1991-01-01

    Reports by U.S. workers on geodetic measurements of recent plate motions or crustal deformation published in 1987-1990 are reviewed. The review begins with global plate motions, proceeds through plate boundaries in California, Alaska, and the Pacific Northwest, and finishes with volcanic phenomena, monument stability and longevity, and GPS relative position measurements. 184 refs.

  11. Present-day plate motions

    NASA Technical Reports Server (NTRS)

    Minster, J. B.; Jordan, T. H.

    1977-01-01

    A data set comprising 110 spreading rates, 78 transform fault azimuths and 142 earthquake slip vectors was inverted to yield a new instantaneous plate motion model, designated RM2. The mean averaging interval for the relative motion data was reduced to less than 3 My. A detailed comparison of RM2 with angular velocity vectors which best fit the data along individual plate boundaries indicates that RM2 performs close to optimally in most regions, with several notable exceptions. On the other hand, a previous estimate (RM1) failed to satisfy an extensive set of new data collected in the South Atlantic Ocean. It is shown that RM1 incorrectly predicts the plate kinematics in the South Atlantic because the presently available data are inconsistent with the plate geometry assumed in deriving RM1. It is demonstrated that this inconsistency can be remedied by postulating the existence of internal deformation with the Indian plate, although alternate explanations are possible.

  12. Image and Reality in African Interethnic Relations: The Fulbe and Their Neighbors. Studies in Third World Societies, Publication Number Eleven.

    ERIC Educational Resources Information Center

    Schultz, Emily A., Ed.

    The eight articles in this collection focus on the Fulbe culture in West Africa, its intragroup relationships as well as its relations with other ethnic groups. Each article relates the concept of ethnicity to social and political differentiation among tribes. Following an introduction by Emily Schultz, John Lewis presents the findings of three…

  13. Intermittent Plate Tectonics

    NASA Astrophysics Data System (ADS)

    Silver, P. G.; Behn, M. D.

    2006-12-01

    Intermittent Plate Tectonics A basic premise of Earth Science is that plate tectonics has been continuously operating since it began early in Earth's history. Yet, plate-tectonic theory itself, specifically the collisional phase of the Wilson Cycle, constitutes a process that is capable of stopping all plate motion. The plausibility of a plate-tectonic hiatus is most easily illustrated by considering the expected future of the present-day plate-tectonic configuration. Since the opening of the Atlantic at ~200 ma, the area of the Atlantic basin has been growing at the expense of the Pacific. If this trend continues, relative plate motion models predict that in ~350 my, the Pacific Ocean basin will effectively close leading to widespread continent-continent collisions. Since a continent-continent collision represents the termination of subduction locally, the accumulated effect of all collisions is to stop subduction globally. In this scenario, ridges would then stop spreading and young oceanic lithosphere would cool, reaching a steady-state thickness of 100 km in about 80 my, based on the properties of oceanic lithosphere today. This would constitute the stoppage of plate tectonics. The presumption that plate tectonics never stops in the face of continental collisions is equivalent to requiring that subduction flux is approximately constant through time, such that subduction initiation roughly balances subduction termination. Such a balance then raises several questions about the subduction initiation process. When and how does subduction initiate? Is there a detectible relationship between subduction cessation and subduction initiation? We can gain some guidance into these questions by examining the plate motion history over the last 200 my. Subduction initiation has occurred over the last 80 my in three intra- oceanic subduction zones: Aleutians, Marianas-Izu-Bonin and Tonga-Kermadec in the Pacific basin. In these cases, however, subduction initiation would not

  14. Obesity and African Americans

    MedlinePlus

    ... Data > Minority Population Profiles > Black/African American > Obesity Obesity and African Americans African American women have the ... ss6304.pdf [PDF | 3.38MB] HEALTH IMPACT OF OBESITY More than 80 percent of people with type ...

  15. Corrugated cover plate for flat plate collector

    DOEpatents

    Hollands, K. G. Terry; Sibbitt, Bruce

    1978-01-01

    A flat plate radiant energy collector is providing having a transparent cover. The cover has a V-corrugated shape which reduces the amount of energy reflected by the cover away from the flat plate absorber of the collector.

  16. Social context of human immunodeficiency virus transmission in Africa: historical and cultural bases of east and central African sexual relations.

    PubMed

    Larson, A

    1989-01-01

    The literature relating to the social context of sexual relations in East and Central Africa has several implications for the heterosexual transmission of human immunodeficiency virus (HIV). Colonially created cities in the region still discriminate economically and socially against women. Rapid urbanization is occurring, but migrants maintain strong ties with rural areas. Traditional attitudes towards marriage and sexuality affect urban behavior in the extent of marital stability, the frequency of polygyny, and the emotional bond between spouses. Ethnic groups in Kampala and Nairobi exemplify the cultural foundations of two forms of sexual relations found in the region, one characterized by prostitution and the other by small circles of interchanging lovers. The first results in a more rapid spread of HIV through the urban population and outwards into rural areas. Each pattern exerts unique constraints on behavioral change and requires different prevention campaigns. PMID:2682946

  17. Decision-making orientation and AIDS-related knowledge, attitudes, and behaviors of Hispanic, African-American, and white adolescents.

    PubMed

    Langer, L M; Zimmerman, R S; Warheit, G J; Duncan, R C

    1993-05-01

    How adolescents' personal sense of directedness (i.e., peer, parent, or self-directed orientation) affects the decision-making processes of adolescent students regarding AIDS-related knowledge, attitudes, beliefs, behaviors, and skills (KABBS) is examined. The sample consisted of 10th-grade students in 8 public high schools (N = 2,515) in Dade County (greater Miami), Florida. The findings showed that decision-making orientation and directedness was a significant predictor of AIDS-related KABBS of adolescents. Overall, the level of AIDS-related KABBS that were associated with low risk was found significantly more often among self-directed students and least often among peer-directed students. The findings of this study suggest that future preadult health-risk research should incorporate the concept of differences of information processing across adolescents. PMID:8500453

  18. Polymorphism of the human factor H-related gene (FHR-1) and of factor H in a West African individual

    SciTech Connect

    Meyer, C.G.; Skerka, C.; Zipfel, P.F.

    1995-03-01

    The human factor H-related 1 (FHR-1) protein is structurally and immunogenically related to the regulatory complement protein factor H (FH). Polymorphism of the FHR-1 gene is indicated by the nucleotide differences as described by the five cDNA clones isolated so far. In order to further analyze this polymorphism we identified PCR-primers which allow the simultaneous amplification of FHR-1 and FH alleles in a single polymerase chain reaction (PCR). By DNA sequence analysis, two novel FHR-1 variants and one as yet unrecognized FH allele could be characterized in an individual from Benin, West Africa. 2 refs., 1 fig.

  19. Challenging empowerment: AIDS-affected South African children and the need for a multi-level relational approach.

    PubMed

    Ansell, Nicola

    2014-01-01

    Critics of empowerment have highlighted the concept's mutability, focus on individual transformation, one-dimensionality and challenges of operationalisation. Relating these critiques to children's empowerment raises new challenges. Drawing on scholarship on children's subjecthood and exercise of power, alongside empirical research with children affected by AIDS, I argue that empowerment envisaged as individual self-transformation and increased capacity to act independently offers little basis for progressive change. Rather it is essential to adopt a relational approach that recognises the need to transform power relationships at multiple levels. This analysis has implications for our wider understanding of empowerment in the 21st century.

  20. Violence Exposure and Health-Related Risk among African American Adolescent Female Detainees: A Strategy for Reducing Recidivism

    ERIC Educational Resources Information Center

    Woodson, Kamilah M.; Hives, Courtney C.; Sanders-Phillips, Kathy

    2010-01-01

    Juvenile crime and violent victimization continue to be significant social problems, in that adolescents, females in particular, are likely to participate in health-related risk behaviors as a result of having been victimized or exposed to a violent environment. Specifically, abuse, neglect, sexual molestation, poverty, and witnessing violence are…

  1. Lipoprotein receptor-related protein 1 variants and dietary fatty acids: meta-analysis of European origin and African American studies

    PubMed Central

    Smith, CE; Ngwa, J; Tanaka, T; Qi, Q; Wojczynski, MK; Lemaitre, RN; Anderson, JS; Manichaikul, A; Mikkilä, V; van Rooij, FJA; Ye, Z; Bandinelli, S; Frazier-Wood, AC; Houston, DK; Hu, F; Langenberg, C; McKeown, NM; Mozaffarian, D; North, KE; Viikari, J; Zillikens, MC; Djoussé, L; Hofman, A; Kähönen, M; Kabagambe, EK; Loos, RJF; Saylor, GB; Forouhi, NG; Liu, Y; Mukamal, KJ; Chen, Y-DI; Tsai, MY; Uitterlinden, AG; Raitakari, O; van Duijn, CM; Arnett, DK; Borecki, IB; Cupples, LA; Ferrucci, L; Kritchevsky, SB; Lehtimäki, T; Qi, Lu; Rotter, JI; Siscovick, DS; Wareham, NJ; Witteman, JCM; Ordovás, JM; Nettleton, JA

    2013-01-01

    OBJECTIVE Low-density lipoprotein-related receptor protein 1 (LRP1) is a multi-functional endocytic receptor and signaling molecule that is expressed in adipose and the hypothalamus. Evidence for a role of LRP1 in adiposity is accumulating from animal and in vitro models, but data from human studies are limited. The study objectives were to evaluate (i) relationships between LRP1 genotype and anthropometric traits, and (ii) whether these relationships were modified by dietary fatty acids. DESIGN AND METHODS We conducted race/ethnic-specific meta-analyses using data from 14 studies of US and European whites and 4 of African Americans to evaluate associations of dietary fatty acids and LRP1 genotypes with body mass index (BMI), waist circumference and hip circumference, as well as interactions between dietary fatty acids and LRP1 genotypes. Seven single-nucleotide polymorphisms (SNPs) of LRP1 were evaluated in whites (N up to 42 000) and twelve SNPs in African Americans (N up to 5800). RESULTS After adjustment for age, sex and population substructure if relevant, for each one unit greater intake of percentage of energy from saturated fat (SFA), BMI was 0.104 kg m−2 greater, waist was 0.305 cm larger and hip was 0.168 cm larger (all P<0.0001). Other fatty acids were not associated with outcomes. The association of SFA with outcomes varied by genotype at rs2306692 (genotyped in four studies of whites), where the magnitude of the association of SFA intake with each outcome was greater per additional copy of the T allele: 0.107 kg m−2 greater for BMI (interaction P=0.0001), 0.267 cm for waist (interaction P=0.001) and 0.21 cm for hip (interaction P=0.001). No other significant interactions were observed. CONCLUSION Dietary SFA and LRP1 genotype may interactively influence anthropometric traits. Further exploration of this, and other diet x genotype interactions, may improve understanding of interindividual variability in the relationships of dietary factors with

  2. Evaluation of the Interplate and Intraplate Deformations of the African Continent Using cGNSS Data

    NASA Astrophysics Data System (ADS)

    Apolinário, J. P.; Fernandes, R. M. S.; Bos, M. S.; Meghraoui, M.; Miranda, J. M. A.

    2014-12-01

    Two main plates, Nubia and Somalia, plus some few more tectonic blocks in the East African Rift System (EARS) delimit the African continent. The major part of the external plate boundaries of Africa is well defined by oceanic ridge systems with the exception of the Nubia-Eurasia complex convergence-collision tectonic zone. In addition, the number and distribution of the tectonic blocks along the EARS region is a major scientific issue that has not been completely answered so far. Nevertheless, the increased number of cGNSS (continuous Global Navigation Satellite Systems) stations in Africa with sufficient long data span is helping to better understand and constrain the complex sub-plate distribution in the EARS as well as in the other plate boundaries of Africa. This work is the geodetic contribution for the IGCP-Project 601 - "Seismotectonics and Seismic Hazards in Africa". It presents the current tectonic relative motions of the African continent based on the analysis of the estimated velocity field derived from the existing network of cGNSS stations in Africa and bordering plate tectonics. For the majority of the plate pairs, we present the most recent estimation of their relative velocity using a dedicated processing. The velocity solutions are computed using HECTOR, a software that takes into account the existing temporal correlations between the daily solutions of the stations. It allows to properly estimate the velocity uncertainties and to detect any artifacts in the time-series. For some of the plate pairs, we compare our solutions of the angular velocities with other geodetic and geophysical models. In addition, we also study the sensitivity of the derived angular velocity to changes in the data (longer data-span for some stations) for tectonic units with few stations, and in particular for the Victoria and Rovuma blocks of the EARS. Finally, we compute estimates of velocity fields for several sub-regions correlated with the seismotectonic provinces and

  3. Adolescent experiences of violence and relation to violence perpetration beyond young adulthood among an urban sample of Black and African American males.

    PubMed

    Reed, Elizabeth; Lawrence, Danielle A; Santana, M C; Welles, C Seth L; Horsburgh, C Robert; Silverman, Jay G; Rich, John A; Raj, Anita

    2014-02-01

    The purpose of this study is to determine if experiences of physical violence during early and late adolescence (12-21 years) places urban Black males at increased risk for interpersonal violence perpetration beyond young adulthood (30 years and older). Participants of this cross-sectional study were Black and African American men (N = 455) between the ages of 30 and 65 years, recruited from four urban clinical sites in the Northeast. Multivariate logistic regression models were used to analyze the relation of adolescent experiences of violence to: (1) past 6 month street violence involvement and (2) past year intimate partner violence perpetration. Ten percent of the sample reported that they experienced adolescent victimization. Men reporting adolescent victimization were significantly more likely to report past 6-month street violence involvement (Adjusted Odds Ratio (AOR) = 3.2, 95 % CI = 1.7-6.3) and past 6 month intimate partner violence perpetration (AOR = 2.8, 95 % CI = 1.8-5.4) compared to men who did not report such victimization. Study findings suggest that in order to prevent adulthood perpetration of violence, more work is needed to address experiences of victimization among young Black males, particularly violence experienced during adolescence.

  4. Impact of Antiretroviral Therapy on Health-Related Quality of Life among South African Women in the CAPRISA 002 Acute Infection Study

    PubMed Central

    Tomita, Andrew; Garrett, Nigel; Werner, Lise; Burns, Jonathan K.; Ngcobo, Nelisiwe; Zuma, Nomthandazo; Mlisana, Koleka; van Loggerenberg, Francois; Abdool Karim, Salim S.

    2014-01-01

    Concerns are often raised regarding potentially adverse effects of antiretroviral therapy (ART) on health-related quality of life (HRQoL), but there is limited longitudinal data to prove this. Building on our prior investigation, we examined the impact of ART on HRQoL among HIV-infected South African women with extensive follow-up in the CAPRISA 002 Acute Infection Cohort Study. Overall HRQoL and five sub-domains [physical well-being (PWB), emotional well-being (EWB), functional and global well-being (FGWB), social well-being (SWB) and cognitive functioning (CF)] were assessed using the Functional Assessment of HIV Infection (FAHI) instrument. Our analyses comparing FAHI scores between pre-ART (established infection) and ART phases using paired Wilcoxon signed-rank tests and adjusted mixed-effects regression models revealed improvements on ART in overall HRQoL, and in PWB, EWB, and SWB, but not in FGWB and CF. No long-term adverse impact of ART on HRQoL was detected, providing additional non-biomedical support to early treatment strategies. PMID:24849623

  5. A deletion variant of the alpha2b-adrenoceptor is related to emotional memory in Europeans and Africans.

    PubMed

    de Quervain, Dominique J-F; Kolassa, Iris-Tatjana; Ertl, Verena; Onyut, P Lamaro; Neuner, Frank; Elbert, Thomas; Papassotiropoulos, Andreas

    2007-09-01

    Emotionally arousing events are recalled better than neutral events. This phenomenon, which helps us to remember important and potentially vital information, depends on the activation of noradrenergic transmission in the brain. Here we show that a deletion variant of ADRA2B, the gene encoding the alpha2b-adrenergic receptor, is related to enhanced emotional memory in healthy Swiss subjects and in survivors of the Rwandan civil war who experienced highly aversive emotional situations. PMID:17660814

  6. Age-related changes in insulin sensitivity and β-cell function among European-American and African-American women.

    PubMed

    Chandler-Laney, Paula C; Phadke, Radhika P; Granger, Wesley M; Fernández, José R; Muñoz, Julian A; Man, Chiara Dalla; Cobelli, Claudio; Ovalle, Fernando; Gower, Barbara A

    2011-03-01

    Type 2 diabetes (T2D) is more prevalent among African-American (AA) than European-American (EA) women for reasons that are unknown. Ethnic differences in physiological processes related to insulin sensitivity (S(I)) and secretion, and age-related changes in these processes, may play a role. The purpose of this study was to identify ethnicity- and age-related differences in S(I) and β-cell responsivity among AA and EA females, and to determine whether these differences are independent of body composition and fat distribution. Healthy, normoglycemic females aged 7-12 years (n = 62), 18-32 years (n = 57), and 40-70 years (n = 49) were recruited for entry into this study. Following an overnight fast, S(I), intravenous glucose tolerance (Kg), acute C-peptide secretion (X0), and basal, first-phase, second-phase, and total β-cell responsivity to glucose (PhiB, Phi1, Phi2, and Phi(TOT), respectively) were measured by an intravenous glucose tolerance test. Total % body fat was assessed by dual-energy X-ray absorptiometry, and intra-abdominal adiposity (IAAT) by computed tomography. Main effects of age group and ethnicity were measured with analysis of covariance, adjusting for % fat, IAAT, and S(I) as indicated. AA had lower S(I), and higher Kg, X0, Phi1, and Phi(TOT) (P < 0.05), which remained after adjustment for % fat and IAAT. Greater X0, Phi1, and Phi(TOT) among AA were independent of S(I). Advancing age was associated with greater Phi2 among both EA and AA. To conclude, inherent ethnic differences in β-cell function exist independently of adiposity and S(I). Future research should examine whether ethnic differences in β-cell physiology contribute to disparities in T2D risk.

  7. Martian plate tectonics

    NASA Astrophysics Data System (ADS)

    Sleep, N. H.

    1994-03-01

    The northern lowlands of Mars have been produced by plate tectonics. Preexisting old thick highland crust was subducted, while seafloor spreading produced thin lowland crust during late Noachian and Early Hesperian time. In the preferred reconstruction, a breakup margin extended north of Cimmeria Terra between Daedalia Planum and Isidis Planitia where the highland-lowland transition is relatively simple. South dipping subduction occured beneath Arabia Terra and east dipping subduction beneath Tharsis Montes and Tempe Terra. Lineations associated with Gordii Dorsum are attributed to ridge-parallel structures, while Phelegra Montes and Scandia Colles are interpreted as transfer-parallel structures or ridge-fault-fault triple junction tracks. Other than for these few features, there is little topographic roughness in the lowlands. Seafloor spreading, if it occurred, must have been relatively rapid. Quantitative estimates of spreading rate are obtained by considering the physics of seafloor spreading in the lower (approx. 0.4 g) gravity of Mars, the absence of vertical scarps from age differences across fracture zones, and the smooth axial topography. Crustal thickness at a given potential temperature in the mantle source region scales inversely with gravity. Thus, the velocity of the rough-smooth transition for axial topography also scales inversely with gravity. Plate reorganizations where young crust becomes difficult to subduct are another constraint on spreading age. Plate tectonics, if it occurred, dominated the thermal and stress history of the planet. A geochemical implication is that the lower gravity of Mars allows deeper hydrothermal circulation through cracks and hence more hydration of oceanic crust so that more water is easily subducted than on the Earth. Age and structural relationships from photogeology as well as median wavelength gravity anomalies across the now dead breakup and subduction margins are the data most likely to test and modify hypotheses

  8. Understanding traditional African healing

    PubMed Central

    MOKGOBI, M.G.

    2015-01-01

    Traditional African healing has been in existence for many centuries yet many people still seem not to understand how it relates to God and religion/spirituality. Some people seem to believe that traditional healers worship the ancestors and not God. It is therefore the aim of this paper to clarify this relationship by discussing a chain of communication between the worshipers and the Almighty God. Other aspects of traditional healing namely types of traditional healers, training of traditional healers as well as the role of traditional healers in their communities are discussed. In conclusion, the services of traditional healers go far beyond the uses of herbs for physical illnesses. Traditional healers serve many roles which include but not limited to custodians of the traditional African religion and customs, educators about culture, counselors, social workers and psychologists. PMID:26594664

  9. Salinity-related variation in gene expression in wild populations of the black-chinned tilapia from various West African coastal marine, estuarine and freshwater habitats

    NASA Astrophysics Data System (ADS)

    Tine, Mbaye; McKenzie, David J.; Bonhomme, François; Durand, Jean-Dominique

    2011-01-01

    This study measured the relative expression of the genes coding for Na +, K +-ATPase 1α(NAKA), voltage-dependent anion channel (VDAC), cytochrome c oxidase-1 (COX), and NADH dehydrogenase (NDH), in gills of six wild populations of a West African tilapia species, acclimatised to a range of seasonal (rainy or dry) salinities in coastal, estuarine and freshwater sites. Previous laboratory experiments have demonstrated that these genes, involved in active ion transport, oxidative phosphorylation, and intra-cellular ATP transport, are relatively over-expressed in gill tissues of this species acclimated to high salinity. Positive correlations between relative expression and ambient salinity were found for all genes in the wild populations (Spearman rank correlation, p < 0.05), although for some genes these were only significant in either the rainy season or dry season. Most significantly, however, relative expression was positively correlated amongst the four genes, indicating that they are functionally interrelated in adaptation of Sarotherodon melanotheron to salinity variations in its natural environment. In the rainy season, when salinity was unstable and ranged between zero and 37 psu across the sites, overall mean expression of the genes was higher than in the dry season, which may have reflected more variable particularly sudden fluctuations in salinity and poorer overall water quality. In the dry season, when the salinity is more stable but ranged between zero and 100 psu across the sites, NAKA, NDH and VDAC expression revealed U-shaped relationships with lowest relative expression at salinities approaching seawater, between 25 and 45 psu. Although it is not simple to establish direct relationship between gene expression levels and energy requirement for osmoregulation, these results may indicate that costs of adaptation to salinity are lowest in seawater, the natural environment of this species. While S. melanotheron can colonise environments with extremely

  10. Babies who die from labour-related intrapartum hypoxia: a confidential enquiry in South African public hospitals.

    PubMed

    Buchmann, E J; Pattinson, R C

    2006-01-01

    Seventeen hospitals, from a range of health-care environments, participated in confidential enquiries of perinatal deaths resulting from labour-related intrapartum hypoxia. There were 102 deaths, including 22 stillbirths and 80 neonatal deaths. The mean birthweight was 3021 g. The active phase of the first stage of labour was prolonged beyond 12 h in six cases, and oxytocin was used for induction or augmentation in 10 women. Fetal heart decelerations were detected in 39 (49%) of the babies that went on to die in the neonatal period, and meconium passage was evident in 50 (63%). There were six breech presentations, and seven cases of cord prolapse. The majority of these deaths occurred in low-risk women with apparently uncomplicated labour. There appears to be a failure to detect or respond to evidence of fetal distress. Intrapartum care for all women in labour requires close attention to detail in monitoring fetal health.

  11. Shedding dynamics of Morogoro virus, an African arenavirus closely related to Lassa virus, in its natural reservoir host Mastomys natalensis

    PubMed Central

    Borremans, Benny; Vossen, Raphaël; Becker-Ziaja, Beate; Gryseels, Sophie; Hughes, Nelika; Van Gestel, Mats; Van Houtte, Natalie; Günther, Stephan; Leirs, Herwig

    2015-01-01

    Arenaviruses can cause mild to severe hemorrhagic fevers. Humans mainly get infected through contact with infected rodents or their excretions, yet little is known about transmission dynamics within rodent populations. Morogoro virus (MORV) is an Old World arenavirus closely related to Lassa virus with which it shares the same host species Mastomys natalensis. We injected MORV in its host, and sampled blood and excretions at frequent intervals. Infection in adults was acute; viral RNA disappeared from blood after 18 days post infection (dpi) and from excretions after 39 dpi. Antibodies were present from 7 dpi and never disappeared. Neonatally infected animals acquired a chronic infection with RNA and antibodies in blood for at least 3 months. The quantified excretion and antibody patterns can be used to inform mathematical transmission models, and are essential for understanding and controlling transmission in the natural rodent host populations. PMID:26022445

  12. Hepatitis C in African Americans.

    PubMed

    Saab, Sammy; Jackson, Christian; Nieto, Jose; Francois, Fritz

    2014-10-01

    The care of hepatitis C virus (HCV) in African Americans represents an opportunity to address a major health disparity in medicine. In all facets of HCV infection, African Americans are inexplicably affected, including in the prevalence of the virus, which is higher among them compared with most of the racial and ethnic groups. Ironically, although fibrosis rates may be slow, hepatocellular carcinoma and mortality rates appear to be higher among African Americans. Sustained viral response (SVR) rates have historically significantly trailed behind Caucasians. The reasons for this gap in SVR are related to both viral and host factors. Moreover, low enrollment rates in clinical trials hamper the study of the efficacy of anti-viral therapy. Nevertheless, the gap in SVR between African Americans and Caucasians may be narrowing with the use of direct-acting agents. Gastroenterologists, hepatologists, primary care physicians, and other health-care providers need to address modifiable risk factors that affect the natural history, as well as treatment outcomes, for HCV among African Americans. Efforts need to be made to improve awareness among health-care providers to address the differences in screening and referral patterns for African Americans.

  13. Africans in America.

    ERIC Educational Resources Information Center

    Hart, Ayanna; Spangler, Earl

    This book introduces African-American history and culture to children. The first Africans in America came from many different regions and cultures, but became united in this country by being black, African, and slaves. Once in America, Africans began a long struggle for freedom which still continues. Slavery, the Civil War, emancipation, and the…

  14. Therapy with African Families.

    ERIC Educational Resources Information Center

    Nwadiora, Emeka

    1996-01-01

    Informs helping professionals about the unique history and challenges of African families to guide them toward providing ethnically sensitive psychological services to African immigrant families in need. African families undergo great stress when faced with the alienation of being Black and African in a Euro-American culture. (SLD)

  15. African Outreach Workshop 1974.

    ERIC Educational Resources Information Center

    Schmidt, Nancy J.

    This report discusses the 1974 African Outreach Workshop planned and coordinated by the African Studies Program at the University of Illinois at Urbana-Champaign. Its major aim was to assist teachers in developing curriculum units on African using materials available in their local community. A second aim was for the African Studies Program to…

  16. Mind-Body Interventions to Reduce Risk for Health Disparities Related to Stress and Strength Among African American Women: The Potential of Mindfulness-Based Stress Reduction, Loving-Kindness, and the NTU Therapeutic Framework.

    PubMed

    Woods-Giscombé, Cheryl L; Black, Angela R

    2010-12-14

    In the current article, the authors examine the potential role of mind-body interventions for preventing or reducing health disparities in a specific group-African American women. The authors first discuss how health disparities affect this group, including empirical evidence regarding the influence of biopsychosocial processes (e.g., psychological stress and social context) on disparate health outcomes. They also detail how African American women's unique stress experiences as a result of distinct sociohistorical and cultural experiences related to race and gender potentially widen exposure to stressors and influence stress responses and coping behaviors. Using two independent, but related, frameworks (Superwoman Schema [SWS] and the Strong Black Woman Script [SBW-S]), they discuss how, for African American women, stress is affected by "strength" (vis-à-vis resilience, fortitude, and self-sufficiency) and the emergent health-compromising behaviors related to strength (e.g., emotional suppression, extraordinary caregiving, and self-care postponement). The authors then describe the potential utility of three mind-body interventions-mindfulness-based stress reduction (MBSR), loving-kindness meditation (LKM), and NTU psychotherapy-for specifically targeting the stress-, strength-, and contextually related factors that are thought to influence disparate outcomes for African American women. Self-awareness, self-care, inter- and intrapersonal restorative healing and a redefinition of inner strength may manifest through developing a mindfulness practice to decrease stress-related responses; using LKM to cultivate compassion and forgiveness for self and others; and the balance of independence and interdependence as a grounding NTU principle for redefining strength. The authors conclude with a discussion of potential benefits for integrating key aspects of the interventions with recommendations for future research.

  17. Mind-Body Interventions to Reduce Risk for Health Disparities Related to Stress and Strength Among African American Women: The Potential of Mindfulness-Based Stress Reduction, Loving-Kindness, and the NTU Therapeutic Framework

    PubMed Central

    Woods-Giscombé, Cheryl L.; Black, Angela R.

    2011-01-01

    In the current article, the authors examine the potential role of mind-body interventions for preventing or reducing health disparities in a specific group—African American women. The authors first discuss how health disparities affect this group, including empirical evidence regarding the influence of biopsychosocial processes (e.g., psychological stress and social context) on disparate health outcomes. They also detail how African American women's unique stress experiences as a result of distinct sociohistorical and cultural experiences related to race and gender potentially widen exposure to stressors and influence stress responses and coping behaviors. Using two independent, but related, frameworks (Superwoman Schema [SWS] and the Strong Black Woman Script [SBW-S]), they discuss how, for African American women, stress is affected by “strength” (vis-à-vis resilience, fortitude, and self-sufficiency) and the emergent health-compromising behaviors related to strength (e.g., emotional suppression, extraordinary caregiving, and self-care postponement). The authors then describe the potential utility of three mind-body interventions—mindfulness-based stress reduction (MBSR), loving-kindness meditation (LKM), and NTU psychotherapy—for specifically targeting the stress-, strength-, and contextually related factors that are thought to influence disparate outcomes for African American women. Self-awareness, self-care, inter- and intrapersonal restorative healing and a redefinition of inner strength may manifest through developing a mindfulness practice to decrease stress-related responses; using LKM to cultivate compassion and forgiveness for self and others; and the balance of independence and interdependence as a grounding NTU principle for redefining strength. The authors conclude with a discussion of potential benefits for integrating key aspects of the interventions with recommendations for future research. PMID:21479157

  18. Sputtering and ion plating

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The proceedings of a conference on sputtering and ion plating are presented. Subjects discussed are: (1) concepts and applications of ion plating, (2) sputtering for deposition of solid film lubricants, (3) commercial ion plating equipment, (4) industrial potential for ion plating and sputtering, and (5) fundamentals of RF and DC sputtering.

  19. Miocene to Pliocene changes in South African hydrology and vegetation in relation to the expansion of C4 plants

    NASA Astrophysics Data System (ADS)

    Dupont, Lydie M.; Rommerskirchen, Florian; Mollenhauer, Gesine; Schefuß, Enno

    2013-08-01

    The Miocene expansion of C4 plants (mainly tropical grasses) between 8 and 4 million years (Ma) remains an enigma since regional differences in the timing of the expansion rules out decreased CO2 (pCO2) as a dominant forcing [e.g. Tipple and Pagani, 2007. The early origins of terrestrial C4 photosynthesis. Annu. Rev. Earth Planet. Sci. 35, 435-461]. Other environmental factors, such as low-latitude aridity and seasonality have been proposed to explain the low tree versus grass ratio found in savannahs and tropical grasslands of the world, but conclusive evidence is missing. Here we use pollen and stable carbon (δ13C) and hydrogen (δD) isotope ratios of terrestrial plant wax from a South Atlantic sediment core (ODP Site 1085) to reconstruct Miocene to Pliocene changes of vegetation and rainfall regime of western southern Africa. Our results reveal changes in the relative amount of precipitation and indicate a shift of the main moisture source from the Atlantic to the Indian Ocean during the onset of a major aridification 8 Ma ago. We emphasize the importance of declining precipitation during the expansion of C4 and CAM (mainly succulent) vegetation in South Africa. We suggest that the C4 plant expansion resulted from an increased equator-pole temperature gradient caused by the initiation of strong Atlantic Meridional Overturning Circulation following the shoaling of the Central American Seaway during the Late Miocene.

  20. Wildlife-associated zoonotic diseases in some southern African countries in relation to game meat safety: a review.

    PubMed

    Bekker, Johan L; Hoffman, Louw C; Jooste, Piet J

    2012-01-01

    With on-going changes in land use practices from conventional livestock farming to commercial, wildlife-based activities, the interface or interaction between livestock and wildlife is increasing. As part of the wildlife-based activities of ecotourism, breeding and hunting, game farmers are also exploring the utilisation of meat from hunted or harvested game. The expanding interface or increased interaction between livestock and wildlife increases the risk of disease incidence and the emergence of new diseases or the re-emergence of previously diagnosed diseases. The risk is not only related to domestic and wild animal health, but also to the occupational hazards that it poses to animal handlers and the consumers of game meat. This review endeavours to highlight the role that game plays in the spreading of zoonotic diseases to other animals and humans. Examples of zoonotic diseases that have occurred in wild animals in the past, their relevance and risk have been summarised and should function as a quick reference guide for wildlife veterinarians, ecologists, farmers, hunters, slaughter staff, processors and public health professionals. PMID:23327327

  1. Wildlife-associated zoonotic diseases in some southern African countries in relation to game meat safety: a review.

    PubMed

    Bekker, Johan L; Hoffman, Louw C; Jooste, Piet J

    2012-12-05

    With on-going changes in land use practices from conventional livestock farming to commercial, wildlife-based activities, the interface or interaction between livestock and wildlife is increasing. As part of the wildlife-based activities of ecotourism, breeding and hunting, game farmers are also exploring the utilisation of meat from hunted or harvested game. The expanding interface or increased interaction between livestock and wildlife increases the risk of disease incidence and the emergence of new diseases or the re-emergence of previously diagnosed diseases. The risk is not only related to domestic and wild animal health, but also to the occupational hazards that it poses to animal handlers and the consumers of game meat. This review endeavours to highlight the role that game plays in the spreading of zoonotic diseases to other animals and humans. Examples of zoonotic diseases that have occurred in wild animals in the past, their relevance and risk have been summarised and should function as a quick reference guide for wildlife veterinarians, ecologists, farmers, hunters, slaughter staff, processors and public health professionals.

  2. Summary of the stratigraphy and structural elements related to plate convergence of the Quetta-Muslim Bagh-Sibi region, Balochistan, west-central Pakistan

    USGS Publications Warehouse

    Maldonado, Florian; Mengal, Jan M.; Khan, Shahid H.; Warwick, Peter D.

    2011-01-01

    The four major faults that bound the structural terrane are the Frontal (F), Ghazaband-Zhob (GZ), Gwal-Bagh (GB), and Chaman (C) faults. Four major periods of deformation are recognized: (1) emplacement of ophiolitic rocks onto the continental margin of the India plate; (2) convergence of the India-Eurasia plates; (3) deposition of Tertiary-Quaternary molasse units followed by major folding and thrusting, and formation of strike-slip faults; and (4) deposition of Pleistocene molasse units with subsequent folding, thrusting, and strike-slip motion that continues to the present.

  3. Difficulties encountered removing locked plates

    PubMed Central

    Raja, S; Imbuldeniya, AM; S, Garg; Groom, G

    2012-01-01

    INTRODUCTION Locked plates are commonly used to obtain fixation in periarticular and comminuted fractures. Their use has also gained popularity in repairing fractures in osteoporotic bone. These plates provide stable fixation and promote biological healing. Over the last 3 years, we have used over 150 locked plates with varying success to fix periarticular fractures involving mainly the knee and ankle. In this study, we report our clinical experience and the difficulties encountered when removing locked plates in adult patients with a variety of indications including implant failure, infection, non-union and a palpable symptomatic implant. METHODS A retrospective analysis was performed of patients enrolled prospectively into a database. Included in the study were 36 consecutive adult patients who each underwent the procedure of locked plate removal in a single inner city level 1 trauma centre. Data collected included primary indication for fixation, indication for implant removal, time of the implant in situ, grade of operating surgeon and difficulties encountered during the procedure. RESULTS Implant removal was associated with a complication rate of 47%. The major problems encountered were difficulty in removing the locked screws and the implant itself. A total of ten cold welded screws were found in eight cases. Removal was facilitated by high speed metal cutting burrs and screw removal sets in all but one case, where a decision was made to leave the plate in situ. CONCLUSIONS The majority of studies investigating implant removal and problems encountered in doing so report a relatively high complication rate. With the advent of locking plates and their growing popularity, difficulties are now being seen intra-operatively when removing them. There is a paucity of data, however, specifically directed at locking plate removal. We recommend that surgeons should be aware of the potential complications while removing locked plates. Fluoroscopic control and all

  4. Plate motion and deformation

    SciTech Connect

    Minster, B.; Prescott, W.; Royden, L.

    1991-02-01

    Our goal is to understand the motions of the plates, the deformation along their boundaries and within their interiors, and the processes that control these tectonic phenomena. In the broadest terms, we must strive to understand the relationships of regional and local deformation to flow in the upper mantle and the rheological, thermal and density structure of the lithosphere. The essential data sets which we require to reach our goal consist of maps of current strain rates at the earth's surface and the distribution of integrated deformation through time as recorded in the geologic record. Our success will depend on the effective synthesis of crustal kinematics with a variety of other geological and geophysical data, within a quantitative theoretical framework describing processes in the earth's interior. Only in this way can we relate the snapshot of current motions and earth structure provided by geodetic and geophysical data with long-term processes operating on the time scales relevant to most geological processes. The wide-spread use of space-based techniques, coupled with traditional geological and geophysical data, promises a revolution in our understanding of the kinematics and dynamics of plate motions over a broad range of spatial and temporal scales and in a variety of geologic settings. The space-based techniques that best address problems in plate motion and deformation are precise space-geodetic positioning -- on land and on the seafloor -- and satellite acquisition of detailed altimetric and remote sensing data in oceanic and continental areas. The overall science objectives for the NASA Solid Earth Science plan for the 1990's, are to Understand the motion and deformation of the lithosphere within and across plate boundaries'', and to understand the dynamics of the mantle, the structure and evolution of the lithosphere, and the landforms that result from local and regional deformation. 57 refs., 7 figs., 2 tabs.

  5. From lizard body form to serpentiform morphology: The atlas-axis complex in African cordyliformes and their relatives.

    PubMed

    Čerňanský, Andrej

    2016-04-01

    The comparative vertebral morphology of the atlas-axis complex in cordyliforms, xantusiid and several skinks is studied here. These lizards are particularly interesting because of their different ecological adaptations and anti-predation strategies, where conformation ranges from the lizard-like body to a snake-like body. This transition to serpentiform morphology shows several evolutionary patterns in the atlas-axis complex: 1) the zygapophyseal articulations are lost in the early stage of the transition. In contrast to mammals, the atlas is more or less locked to the axis in lepidosaurs, but the absence of zygapophyseal articulation releases this locking for rotation. However despite its serpentiform morphology, Chamaesaura is different, in possessing this articulation; 2) the first intercentrum of Chamaesaura and Tetradactylus africanus (serpentiform grass-swimmers) is fully curved anteriorly, underlying the occipital condyle. While this limits ventral skull rotation beyond a certain angle, it locks the skull, which is a crucial adaptation for a sit-and-wait position in grassland habitats that needs to keep the head stabilized; and 3) in Acontias, most of the atlas articular surface with the occipital condyle is formed by the lateral aspect of the articulation area relative to the area located in the dorsal region of the slightly reduced intercentrum. A similar state occurs in amphisbaenians, most likely reflecting a fossorial lifestyle of the limbless lizards. Although Chamaesaura and Tetradactylus live sympatrically in grasslands, Chamaesaura differs in several ways in atlas-axis complex: for example, aforementioned presence of the atlas-axis zygapophyseal articulation, and long posterodorsal processes. Its occipital condyle protrudes further posteriorly, placing the atlas-axis complex further from the endocranium than in Tetradactylus. Hence, adaptation in the same niche, even among sister clades, can lead to different atlas-axis morphology due to different

  6. Proxy Assessment of Health-Related Quality of Life in African American and White Respondents With Prostate Cancer

    PubMed Central

    Pickard, A. Simon; Lin, Hsiang-Wen; Knight, Sara J.; Sharifi, Roohollah; Wu, Zhigang; Hung, Shih-Ying; Witt, Whitney P.; Chang, Chih-Hung; Bennett, Charles L.

    2011-01-01

    Objectives An emerging issue in the proxy literature is whether specifying different proxy viewpoints contributes to different health-related quality of life (HRQL) assessments, and if so, how might each perspective be informative in medical decision making. The aims of this study were to determine if informal caregiver assessments of patients with prostate cancer differed when prompted from both the patient perspective (proxy-patient) and their own viewpoint (proxy-proxy), and to identify factors associated with differences in proxy perspectives (ie, the intraproxy gap). Research Design and Methods Using a cross-sectional design, prostate cancer patients and their informal caregivers were recruited from urology clinics in the Jesse Brown Veterans Affairs Healthcare System in Chicago. Dyads assessed HRQL using the EQ-5D visual analog scale (VAS) and EORTC QLQ-C30. Results Of 87 dyads, most caregivers were female (83%) and were spouses/partners (58%). Mean difference scores between proxy-patient and proxy-proxy perspectives were statistically significant for QLQ-C30 physical and emotional functioning, and VAS (all P < 0.05), with the proxy-patient perspective closer to patient self-report. Emotional functioning had the largest difference, mean 6.0 (SD 12.8), an effect size = 0.47. Factors weakly correlated with the intraproxy gap included relationship (spouse) and proxy gender for role functioning, and health literacy (limited/functional) for physical functioning (all P < 0.05, 0.20 < r < 0.35). Conclusions Meaningful differences between proxy-patient and proxy-proxy perspectives on mental health were consistent with a conceptual framework for understanding proxy perspectives. Prompting different proxy viewpoints on patient health could help clinicians identify patients who may benefit from clinical intervention. PMID:19169118

  7. Relative toxicity of spent lubricant oil and detergent against benthic macro-invertebrates of a west African estuarine lagoon.

    PubMed

    Chukwu, L O; Odunzeh, C C

    2006-07-01

    The relative acute toxicity of spent lubricant oil and detergent was evaluated against hermit crab, Clibanarius africanus (Aurivillus) and periwinkle, Tympanotonus fuscatus (L) from the Lagos lagoon in laboratory bioassays. Based on the derived toxicity indices, the detergent (96 hr LC50 = 5.77ml/l) was found to be 1.73 times more toxic than spent engine oil (96 hr LC50 = 10.01 ml/l) when acting singly against C africanus and 18.73 times (96 hr LC50-48.67 ml/l) more toxic (96 hr LC50 = 911.57 ml/l) when acting singly against T. fuscatus. On the basis of the computed susceptibility factors, C. africanus was found to be about eight times and ninety-one times more susceptible to the toxic effect of detergent and spent lubricant oil respectively. The randomized analysis of variance (ANOVA) showed that there was significant difference (Fcal 58.83 Ftab 3.87; DF 13; p > 0.05) between all treatments of spent lubricant oil and detergent during the 96 hr exposure period of test animals. At 5% level of significance the Student Neuman-Keuls (SNK) test further revealed significant differences in the mean mortality response of test animals exposed to toxicants at all concentrations and untreated control. The results obtained in this study suggest that the estuarine benthic macroinvertebrates, which play key roles in the environment, may serve as useful in-situ sentinels for biomonitoring studies of petroleum pollutants in fragile aquatic ecosystems such as the Lagos lagoon.

  8. Quaternions as astrometric plate constants

    NASA Technical Reports Server (NTRS)

    Jefferys, William H.

    1987-01-01

    A new method for solving problems in relative astrometry is proposed. In it, the relationship between the measured quantities and the components of the position vector of a star is modeled using quaternions, in effect replacing the plate constants of a standard four-plate-constant solution with the four components of a quaternion. The method allows a direct solution for the position vectors of the stars, and hence for the equatorial coordinates. Distortions, magnitude, and color effects are readily incorporated into the formalism, and the method is directly applicable to overlapping-plate problems. The advantages of the method include the simplicity of the resulting equations, their freedom from singularities, and the fact that trigonometric functions and tangential point transformations are not needed to model the plate material. A global solution over the entire sky is possible.

  9. Productivity paradox in the NW African upwelling area during the last glaciation related to changes in nutricline depth and Saharan humid episodes

    NASA Astrophysics Data System (ADS)

    Meggers, H.; Prange, M.; Kuhlmann, H.; Freudenthal, T.; Schulz, M.; Hensen, C.; Plewa, K.

    2009-04-01

    The Sahara is the largest desert of the world. However, during the early Holocene the Saharan realm was nearly completely vegetated within the "African humid period". This period has been attributed to a strengthening and northward extension of the summer monsoon. Our reconstructions of marine productivity and terrigenous input from a sediment core off NW Africa provide a detailed record of subtropical climate from 45,000 to 3,000 years BP. We show that abrupt climatic changes modulated the precessionally forced paleoproductivity-signal off NW Africa. Cold periods with increased upwelling intensity show low productivity due to a deepening of the nutricline depth during the winter bloom. Although the glacial in NW Africa is believed to be a dry and cold period, our data indicate wet phases during the insolation maximum in marine isotopic stage 3. These glacial "Saharan humid episodes" would have offered ecological conditions almost resembling those of the early Holocene. Core GeoB 5546 was retrieved at 27°32`N, 13°44`W at 1070 m water-depth off Cape Yubi. The average sedimentation rate of 20 cm /1000 years is caused by the combined influence of high regional surface ocean productivity and high supply of terrigenous material, partly windblown African mineral dust and partly wadi/river transported material. Along with fourteen 14C-datings, the δ18O-values of the planktonic foraminifera G. bulloides were used for stratigraphy. At present, productivity in the Eastern Boundary Current region of the NE Atlantic is seasonal and closely linked to two major processes, that is, coastal upwelling in summer and deep mixing with an associated bloom in winter. High TOC contents of up to 1.5 % occur during interstadials, whereas lower values (0.6-0.9 %) prevail during stadials. If wind-driven coastal upwelling was the major process that controls the paleoproductivity in the Eastern Boundary Current, this finding would contradict modelling results which indicate strengthened NE

  10. How is Silurian-Early Devonian faulting in the North America continental interior related to orogenic processes at plate boundaries? A working hypothesis from the Canadian North

    NASA Astrophysics Data System (ADS)

    Pinet, Nicolas

    2015-04-01

    The Paleozoic Appalachian/Franklinian orogen that rims the North America continent on its eastern and northern sides is comparable in size with Tethyan orogenic belts. However, the far-field effects in the continental interior of the multiple Ordovician to Carboniferous deformation phases that built the orogen were relatively minor if compared with those associated with the Himalayas and Alps, a characteristics related to the high integrated strength of the North American craton. Despite the generally little deformation of the continental interior, two regional-scale tectonic features preserved evidence of significant Paleozoic tectonism: the fault bounded Hudson Bay Central High (HBCH) and the Boothia uplift/Cornwallis fold belt (BUCF) in the Canadian Arctic. In the Hudson Bay intracratonic basin, the lower part of the sedimentary succession (Upper Ordovician to Lower Devonian) is cut by high-angle faults and overlain by a saucer-shape, essentially underformed sedimentary package (Middle to Upper Devonian). The main structural feature is the NNW-trending HBCH that extends for a minimum length of 500 km with normal faults characterized by throws up to 500 m that were mainly active during the Silurian - Early Devonian period. The >700-km long, N-trending BUCF is nearly perpendicular to the deformation front of the Franklinian mobile belt. In its southern segment (Boothia uplift), its western side is characterized by an east-dipping reverse fault zone that puts Precambrian rocks over Paleozoic strata. In its northern segment (Cornwallis fold belt), the Paleozoic succession is involved in open folds and cuts by steeply dipping reverse faults. Syn-tectonic clastic sediments constrain the age of structures to the latest Silurian-Early Devonian. Comparison of the HBCH and BUCF indicates that they are grossly parallel, partly contemporaneous but with different kinematics. This kinematic variability may be explained if they are genetically linked with different segments of

  11. Diversity among African Pygmies

    PubMed Central

    Ramírez Rozzi, Fernando V.; Sardi, Marina L.

    2010-01-01

    Although dissimilarities in cranial and post-cranial morphology among African pygmies groups have been recognized, comparative studies on skull morphology usually pull all pygmies together assuming that morphological characters are similar among them and different with respect to other populations. The main aim of this study is to compare cranial morphology between African pygmies and non-pygmies populations from Equatorial Africa derived from both the Eastern and the Western regions in order to test if the greatest morphological difference is obtained in the comparison between pygmies and non-pygmies. Thirty three-dimensional (3D) landmarks registered with Microscribe in four cranial samples (Western and Eastern pygmies and non-pygmies) were obtained. Multivariate analysis (generalized Procrustes analysis, Mahalanobis distances, multivariate regression) and complementary dimensions of size were evaluated with ANOVA and post hoc LSD. Results suggest that important cranial shape differentiation does occur between pygmies and non-pygmies but also between Eastern and Western populations and that size changes and allometries do not affect similarly Eastern and Western pygmies. Therefore, our findings raise serious doubt about the fact to consider African pygmies as a homogenous group in studies on skull morphology. Differences in cranial morphology among pygmies would suggest differentiation after divergence. Although not directly related to skull differentiation, the diversity among pygmies would probably suggest that the process responsible for reduced stature occurred after the split of the ancestors of modern Eastern and Western pygmies. PMID:21049030

  12. African horse sickness.

    PubMed

    Zientara, S; Weyer, C T; Lecollinet, S

    2015-08-01

    African horse sickness (AHS) is a devastating disease of equids caused by an arthropod-borne virus belonging to the Reoviridae family, genus Orbivirus. It is considered a major health threat for horses in endemic areas in sub-Saharan Africa. African horse sickness virus (AHSV) repeatedly caused large epizootics in the Mediterranean region (North Africa and southern Europe in particular) as a result of trade in infected equids. The unexpected emergence of a closely related virus, the bluetongue virus, in northern Europe in 2006 has raised fears about AHSV introduction into Europe, and more specifically into AHSV-free regions that have reported the presence of AHSV vectors, e.g. Culicoides midges. North African and European countries should be prepared to face AHSV incursions in the future, especially since two AHSV serotypes (serotypes 2 and 7) have recently spread northwards to western (e.g. Senegal, Nigeria, Gambia) and eastern Africa (Ethiopia), where historically only serotype 9 had been isolated. The authors review key elements of AHS epidemiology, surveillance and prophylaxis. PMID:26601437

  13. Absolute Plate Velocities from Seismic Anisotropy

    NASA Astrophysics Data System (ADS)

    Kreemer, Corné; Zheng, Lin; Gordon, Richard

    2015-04-01

    The orientation of seismic anisotropy inferred beneath plate interiors may provide a means to estimate the motions of the plate relative to the sub-asthenospheric mantle. Here we analyze two global sets of shear-wave splitting data, that of Kreemer [2009] and an updated and expanded data set, to estimate plate motions and to better understand the dispersion of the data, correlations in the errors, and their relation to plate speed. We also explore the effect of using geologically current plate velocities (i.e., the MORVEL set of angular velocities [DeMets et al. 2010]) compared with geodetically current plate velocities (i.e., the GSRM v1.2 angular velocities [Kreemer et al. 2014]). We demonstrate that the errors in plate motion azimuths inferred from shear-wave splitting beneath any one tectonic plate are correlated with the errors of other azimuths from the same plate. To account for these correlations, we adopt a two-tier analysis: First, find the pole of rotation and confidence limits for each plate individually. Second, solve for the best fit to these poles while constraining relative plate angular velocities to consistency with the MORVEL relative plate angular velocities. The SKS-MORVEL absolute plate angular velocities (based on the Kreemer [2009] data set) are determined from the poles from eight plates weighted proportionally to the root-mean-square velocity of each plate. SKS-MORVEL indicates that eight plates (Amur, Antarctica, Caribbean, Eurasia, Lwandle, Somalia, Sundaland, and Yangtze) have angular velocities that differ insignificantly from zero. The net rotation of the lithosphere is 0.25±0.11° Ma-1 (95% confidence limits) right-handed about 57.1°S, 68.6°E. The within-plate dispersion of seismic anisotropy for oceanic lithosphere (σ=19.2° ) differs insignificantly from that for continental lithosphere (σ=21.6° ). The between-plate dispersion, however, is significantly smaller for oceanic lithosphere (σ=7.4° ) than for continental

  14. African (Black) Psychology: Issues and Synthesis.

    ERIC Educational Resources Information Center

    Baldwin, Joseph A.

    1986-01-01

    Reviews the recent attempts of Black psychologists and social scientists to formulate a conceptual-operational framework for the study of psychological phenomena as they bear on the cultural-survival conditions of Black-African people. Outlines issues and problems in the attempt to define African (Black) psychology and discusses its relation to…

  15. Genetics Home Reference: African iron overload

    MedlinePlus

    ... of a genetic condition? Genetic and Rare Diseases Information Center Frequency African iron overload is common in rural areas of central and ... more about the gene associated with African iron overload SLC40A1 Related Information What is a gene? What is a gene ...

  16. African American Males in Counseling: Who's Pulling the Trigger Now?

    ERIC Educational Resources Information Center

    Bethea-Whitfield, Patricia

    African American males face numerous challenges to their physical and psychological well-being. This project is a survey of the literature and trends relative to African American males from 1987 to the present. In reviewing the fifteen years since Parham and McDavis published their now famous article on African American men as an endangered…

  17. Going to School: The African-American Experience.

    ERIC Educational Resources Information Center

    Lomotey, Kofi, Ed.

    This volume presents the views of a range of African-American educators on questions related to African-American academic achievement. The concern in this volume is with the persistent, pervasive, and disproportionate underachievement of African-American students. The book is divided into four parts. Part 1, "Problem Identification," comprises the…

  18. Perceptions of Discrimination and Achievement in African American Students.

    ERIC Educational Resources Information Center

    Rowley, Stephanie Johnson

    This study explored the processes that lead to relatively lower academic performance among African American students. It has been suggested that African American students perceive that, because of discrimination, education is less useful as a tool for upward mobility for African Americans than it is for members of other ethnic groups. The nature…

  19. Geomorphometric reconstruction of post-eruptive surfaces of the Virunga Volcanic Province (East African Rift), constraint of erosion ratio and relative chronology

    NASA Astrophysics Data System (ADS)

    Lahitte, Pierre; Poppe, Sam; Kervyn, Matthieu

    2016-04-01

    Quaternary volcanic landforms result from a complex evolution, involving volcanic constructional events and destructive ones by collapses and long-term erosion. Quantification, by morphometric approaches, of the evolution through time of the volcano shape allows the estimation of relative ages between volcanoes sharing the same climate and eruptive conditions. We apply such method to six volcanoes of the Virunga Volcanic Province in the western branch of the East African Rift Valley that still has rare geochronological constraints. As they have comparable sizes, volcanic history and erupted products, these edifices may have undergone comparable conditions of erosion which justify the deduction of relative chronology from their erosion pattern. Our GIS-based geomorphometric approach, the SHAPEVOLC algorithm, quantifies erupted or dismantled volumes by numerically modeling topographies resulting from the eruptive construction of each volcano. Constraining points are selected by analyses of morphometric properties of each cell of the current DEM, as the loci where the altitude is still representative of the un-eroded volcanic surfaces. A primary elevation surface is firstly adjusted to these constraining points by modeling a first-order pseudo-radial surface defined by: 1. the curve best fitting the concave-upwards volcano profile; 2. the location and elevation of the volcano summit; and 3. the possible eccentricity and azimuth parameters that allow to stretch and contract contours to adjust the shape of the model to the elliptically-shaped surface of the volcano. A second-order surface is next computed by local adjustment of the first-order surface to the constraining points to obtain the definitive primary elevation surface of the considered volcanic construct. Amount of erosion is obtained by summing the difference in elevation between reconstructed surfaces and current ones that allows to establish relative ages of volcanoes. For the 6 studied Virunga volcanoes

  20. Impact on multilayered composite plates

    NASA Technical Reports Server (NTRS)

    Kim, B. S.; Moon, F. C.

    1977-01-01

    Stress wave propagation in a multilayer composite plate due to impact was examined by means of the anisotropic elasticity theory. The plate was modelled as a number of identical anisotropic layers and the approximate plate theory of Mindlin was then applied to each layer to obtain a set of difference-differential equations of motion. Dispersion relations for harmonic waves and correction factors were found. The governing equations were reduced to difference equations via integral transforms. With given impact boundary conditions these equations were solved for an arbitrary number of layers in the plate and the transient propagation of waves was calculated by means of a Fast Fourier Transform algorithm. The multilayered plate problem was extended to examine the effect of damping layers present between two elastic layers. A reduction of the interlaminar normal stress was significant when the thickness of damping layer was increased but the effect was mostly due to the softness of the damping layer. Finally, the problem of a composite plate with a crack on the interlaminar boundary was formulated.

  1. Plate description of active deformation in the Africa (AF)-Arabia (AR)-Eurasia (EU) zone of plate interaction

    NASA Astrophysics Data System (ADS)

    Vernant, P.; McClusky, S.; Reilinger, R.

    2006-12-01

    We present the results of 17 years of GPS monitoring in this zone of plate interaction and show that to the resolution of our observations (i.e., ~1-2 mm/yr; ~ ±10 % of relative plate motions), deformation is consistent with plate-block models with relative motion between adjacent plates/blocks accommodated by elastic strain accumulation. Relative plate motions are consistent with geologically recent (~ 3 Ma) plate motions where geologic estimates of relative plate motion have been determined (AR- Nubia: Red Sea; AR-Somalia: Gulf of Aden; AF-EU; AR-EU). Furthermore, fault slip rates derived from the GPS block motions are mostly equal to geologic slip rates determined for long enough time intervals to average out earthquake cycle effects. We conclude that a plate description (i.e., relative Euler vectors) is appropriate to describe the kinematics of continental deformation during the past few Myr in this zone of plate interaction.

  2. Effectiveness of pre-school- and school-based interventions to impact weight-related behaviours in African American children and youth: a literature review.

    PubMed

    Robinson, L E; Webster, E K; Whitt-Glover, M C; Ceaser, T G; Alhassan, S

    2014-10-01

    This review assessed the effectiveness of pre-school- and school-based obesity prevention and/or treatment interventions targeting healthy eating, physical activity or obesity in African American children and adolescents. Systematic searches were conducted for English-printed research articles published between January 1980 and March 2013. Retained articles included experimental studies conducted in the United States that targeted ≥ 80% African American/black children and adolescents and/or studies whose results were stratified by race/ethnicity, and that were conducted in pre-schools/head start or schools (excluding after-school programmes). Of the 12,270 articles identified, 17 met the inclusion criteria (pre-school, n=2; elementary school, n=7; middle and secondary schools, n=8). Thirteen studies found significant improvements in nutrition (pre-school, n=1; elementary, n=7; secondary, n=5) and three found significant improvements in physical activity (pre-school, n=1; elementary, n=2) variables of interest. Two studies (pre-school, n=1; secondary, n=1) reported significant reductions in obesity in African American children. The evidence available suggests school-based interventions are effective in promoting healthy nutrition behaviours in African American children. Conclusions overall and, particularly, about effects on physical activity and obesity are limited due to the small number of studies, differences in assessment approaches and a lack of follow-up assessments.

  3. African-American Adolescents' Knowledge, Health-Related Attitudes, Sexual Behavior, and Contraceptive Decisions: Implications for the Prevention of Adolescent HIV Infection.

    ERIC Educational Resources Information Center

    St. Lawrence, Janet S.

    1993-01-01

    African-American adolescents (n=195) completed measures on Acquired Immune Deficiency Syndrome (AIDS) knowledge, condoms, health locus of control, vulnerability to human immunodeficiency virus, peer sexual norms, sexual behavior, and contraceptive preferences. Girls were more knowledgeable about AIDS, reported fewer sexual partners, held more…

  4. Frederick Douglass and I: Writing to Read and Relate History with Life among African American Adolescents at a High-Poverty Urban School

    ERIC Educational Resources Information Center

    Morphy, Paul

    2013-01-01

    Purpose: Black history as represented in social studies textbooks often lacks depth demanded by historians and authenticity required for cultural relevance to African American students. However, important Black historical narratives sometimes contain difficult prose and refer to times or circumstances that are far removed from students' life…

  5. A Comparative Analysis Regarding Factors Related to 13- to 18-Year-Old African American Male Adolescents in Special Education and the Justice System

    ERIC Educational Resources Information Center

    Phipps, Jonathan Lanier

    2013-01-01

    This study was focused on the identification of selected risk factors seemingly present among African American male adolescents 13 to 18 years old who were participants in special education programs at their schools. Many of these male adolescents were also found to participate in the juvenile justice system under what was characterized as…

  6. LEADERSHIP TRAINING PROGRAM FOR SELECTED AFRICAN HEALTH SPECIALISTS (WASHINGTON, D.C., SEPTEMBER 12-24, 1965). APPLICATIONS OF HUMAN RELATIONS LABORATORY TRAINING, NUMBER 3, 1966.

    ERIC Educational Resources Information Center

    MIAL, H. CURTIS

    THE AGENCY FOR INTERNATIONAL DEVELOPMENT HAS BEEN TRAINING AFRICAN HEALTH SPECIALISTS IN THE UNITED STATES, BUT LEADERSHIP TRAINING HAS BEEN GIVEN LITTLE ATTENTION. SUCH TRAINING SHOULD HELP THEM OVERCOME DIFFERENCES BETWEEN MODERN TECHNOLOGY AND TRADITIONAL CUSTOMS, DEFINE ORGANIZATIONAL ROLE, RESOLVE STATUS DIFFERENCES, AND GET COOPERATIVE…

  7. Personality Similarity and Work-Related Outcomes among African-American Nursing Personnel: A Test of the Supplementary Model of Person-Environment Congruence.

    ERIC Educational Resources Information Center

    Day, David V.; Bedeian, Arthur G.

    1995-01-01

    Data from 206 nursing service employees (171 African American) and a 5-factor taxonomy of personality were used to test effects of personality similarity on job satisfaction, performance, and tenure. Tenure was significantly predicted by satisfaction and similarity in conscientiousness. No association was found between personality similarity and…

  8. Factors Related to Self-Esteem among African American Youths: A Secondary Analysis of the High/Scope Perry Preschool Data.

    ERIC Educational Resources Information Center

    Luster, Tom; McAdoo, Harriette Pipes

    1995-01-01

    Used Perry Preschool data on 121 African American adolescents to explore correlates of self-esteem. Higher self-esteem scores were expected for youths who had experienced success in areas important to them and who perceived that significant others regarded them highly. Data supported the hypothesis that the effects of teens' accomplishments and…

  9. Role of mantle flow in Nubia-Somalia plate divergence

    NASA Astrophysics Data System (ADS)

    Stamps, D. S.; Iaffaldano, G.; Calais, E.

    2015-01-01

    Present-day continental extension along the East African Rift System (EARS) has often been attributed to diverging sublithospheric mantle flow associated with the African Superplume. This implies a degree of viscous coupling between mantle and lithosphere that remains poorly constrained. Recent advances in estimating present-day opening rates along the EARS from geodesy offer an opportunity to address this issue with geodynamic modeling of the mantle-lithosphere system. Here we use numerical models of the global mantle-plates coupled system to test the role of present-day mantle flow in Nubia-Somalia plate divergence across the EARS. The scenario yielding the best fit to geodetic observations is one where torques associated with gradients of gravitational potential energy stored in the African highlands are resisted by weak continental faults and mantle basal drag. These results suggest that shear tractions from diverging mantle flow play a minor role in present-day Nubia-Somalia divergence.

  10. The African Pediatric Fellowship Program: Training in Africa for Africans.

    PubMed

    Wilmshurst, Jo M; Morrow, Brenda; du Preez, Avril; Githanga, David; Kennedy, Neil; Zar, Heather J

    2016-01-01

    Africa has a significant burden of childhood disease, with relatively few skilled health care professionals. The African Paediatric Fellowship Programme was developed by the Department of Pediatrics and Child Health at the University of Cape Town to provide relevant training for African child health professionals, by Africans, within Africa. Trainees identified by partner academic institutions spend 6 months to 2 years training in the Department of Pediatrics and allied disciplines. They then return to their home institution to build practice, training, research, and advocacy. From 2008 to 2015, 73 physicians have completed or are completing training in general pediatrics or a pediatric subspecialty. At 1 year posttraining, 98% to 100% are practicing back in their home institution. The impact of the returning fellows is evident from their practice interventions, research collaborations, and positions as stakeholders who can change health care policies. Thirty-three centers in 13 African countries are partners with the program, and the program template is now followed by other partner sites in Africa. Increasing and retaining the skills pool of African child health specialists is building a network of motivated, highly skilled clinicians who are equipped to advance child health in Africa. PMID:26659458

  11. The African Pediatric Fellowship Program: Training in Africa for Africans.

    PubMed

    Wilmshurst, Jo M; Morrow, Brenda; du Preez, Avril; Githanga, David; Kennedy, Neil; Zar, Heather J

    2016-01-01

    Africa has a significant burden of childhood disease, with relatively few skilled health care professionals. The African Paediatric Fellowship Programme was developed by the Department of Pediatrics and Child Health at the University of Cape Town to provide relevant training for African child health professionals, by Africans, within Africa. Trainees identified by partner academic institutions spend 6 months to 2 years training in the Department of Pediatrics and allied disciplines. They then return to their home institution to build practice, training, research, and advocacy. From 2008 to 2015, 73 physicians have completed or are completing training in general pediatrics or a pediatric subspecialty. At 1 year posttraining, 98% to 100% are practicing back in their home institution. The impact of the returning fellows is evident from their practice interventions, research collaborations, and positions as stakeholders who can change health care policies. Thirty-three centers in 13 African countries are partners with the program, and the program template is now followed by other partner sites in Africa. Increasing and retaining the skills pool of African child health specialists is building a network of motivated, highly skilled clinicians who are equipped to advance child health in Africa.

  12. In situ rutile petrochronology: texture-related T, Paleoproterozoic inheritance and a Pan-African overprint in the oldest subduction-related eclogites, Usagaran Orogen, Tanzania

    NASA Astrophysics Data System (ADS)

    Moeller, A.; Kraus, K.; Herms, P.; Appel, P.; Raase, P.

    2014-12-01

    Rutile U-Pb thermochronology is applied successfully by both TIMS and beam methods to date cooling events in mafic and metapelitic rocks, as well as in detrital studies. The Zr-in-rutile thermometer is very robust to thermal diffusion, and generally requires complete recrystallization to change recorded crystallization temperatures. Evidence for diffusion of HFSE elements in rutile is sparse; whereas U-Pb chronology generally records diffusion controlled cooling from the last event. This study follows conventional thermobarometry and U-Pb TIMS results on monazite, sphene and rutile of Möller et al. (1995) establishing a 2 Ga eclogite facies event from MORB-like metabasic, and metapelitic rocks in the Usagaran Orogen of Tanzania, interpreted to be the oldest outcrops of subduction-related eclogites. Rutile from both rock types were discordant near a ca. 500 Ma lower intercept, confirming a thermal overprint postulated on the basis of K-Ar and Rb-Sr mica ages by e.g. Wendt et al. (1972). The age of the eclogite-facies event was confirmed by U-Pb zircon dating of a 1991±2 Ma crosscutting pegmatite (Collins et al., 1999). We present in situ LA-ICP-MS rutile petrochronology on five metabasic and metapelitic eclogite facies samples with variable retrograde amphibolite-facies recrystallization. Thermometry confirms conventional Fe-Mg results, including higher peak temperatures in metabasites. Traverses on rutile inclusions in large garnet prophyroblasts in metapelites show increasing temperatures from cores outwards and a slight decrease towards outermost rims, with peak T coinciding with highest Mg# and highest grossular content, hence consistent with preservation of prograde zoning in the garnets and a brief eclogite facies event. Large rutiles (800μm) in recrystallized samples record temperature zoning profiles. U-Pb results show inheritance of near concordant 2 Ga domains, but dominantly confirm the ca. 490 Ma amphibolite facies overprint. The study is an excellent

  13. Provenance change of sediment input in the northeastern foreland of Pamir related to collision of the Indian Plate with the Kohistan-Ladakh arc at around 47 Ma

    NASA Astrophysics Data System (ADS)

    Sun, Jimin; Xiao, Wenjiao; Windley, Brian F.; Ji, Weiqiang; Fu, Bihong; Wang, Jiangang; Jin, Chunsheng

    2016-02-01

    The Pamir plateau forms a prominent tectonic salient that marks the western end of the Himalayan orogen containing several terranes that were accreted to Eurasia from the Late Paleozoic to Cenozoic. A detailed knowledge of the tectonic evolution of the Pamir salient during the Cenozoic is important for our understanding of the intracontinental deformation in the western Himalaya. Although the tectonic evolution of the Pamir salient has long been studied, the timing of collision between the Indian Plate and the Kohistan-Ladakh arc is still a matter of debate. We present new U-Pb ages and Hf isotopes of detrital zircons, magnetic fabrics, and stable isotopes from the foreland basin on the northeastern margin of the Pamir that indicate a change in sediment provenance started at about 47 Ma. Sediments in the southwest Tarim Basin were partially derived from the uplifted and eroded Karakoram and Kohistan terranes created by the collision between the Indian Plate and the Kohistan-Ladakh arc at circa 47 Ma, as a result of northward thrusting and propagation of the Indian Plate under Eurasia.

  14. Earth's Decelerating Tectonic Plates

    SciTech Connect

    Forte, A M; Moucha, R; Rowley, D B; Quere, S; Mitrovica, J X; Simmons, N A; Grand, S P

    2008-08-22

    Space geodetic and oceanic magnetic anomaly constraints on tectonic plate motions are employed to determine a new global map of present-day rates of change of plate velocities. This map shows that Earth's largest plate, the Pacific, is presently decelerating along with several other plates in the Pacific and Indo-Atlantic hemispheres. These plate decelerations contribute to an overall, globally averaged slowdown in tectonic plate speeds. The map of plate decelerations provides new and unique constraints on the dynamics of time-dependent convection in Earth's mantle. We employ a recently developed convection model constrained by seismic, geodynamic and mineral physics data to show that time-dependent changes in mantle buoyancy forces can explain the deceleration of the major plates in the Pacific and Indo-Atlantic hemispheres.

  15. Tethyan collision forces and the stress field of the Eurasian Plate

    NASA Astrophysics Data System (ADS)

    Warners-Ruckstuhl, Karin N.; Govers, Rob; Wortel, Rinus

    2013-10-01

    Resistive forces along convergent plate boundaries have a major impact on surface deformation, most visibly at collisional plate boundaries. Although quantification of these forces is key to understanding the evolution and present state of mountain belts, they remain highly uncertain due to the complexity of plate boundary structures and rheologies. In previous studies of the Eurasian Plate, we have analysed the balance of plate boundary forces, tractions resulting from lithosphere-mantle coupling, and intraplate variations in topography and density structure. This yielded a range of acceptable force distributions. In this study, we investigate to which extent the observed present-day stress field provides further constraints on the distribution of forces. We address the dynamics of the Eurasian Plate as a whole. This enables us to base our analysis on mechanical equilibrium of a tectonic plate and to evaluate all forces as part of an internally consistent set of forces driving and deforming Eurasia. We incorporate tractions from convective mantle flow modelling in a lithospheric model in which edge and lithospheric body forces are modelled explicitly and compute resulting stresses in a homogeneous elastic thin shell. Intraplate stress observations used are from the World Stress Map project. Eurasia's stress field turns out to be particularly sensitive to the distribution of collision forces on the plate's southern margin and, to a much lesser extent, to lithospheric density structure and tractions from mantle flow. Stress observations require collision forces on the India-Eurasia boundary of 7.0-10.5 TN m-1 and on the Arabia-Eurasia boundary of 1.3-2.7 TN m-1. Implication of mechanical equilibrium of the plate is that forces on the contacts with the African and Australian plates amount to 1.0-2.5 and 0-1.3 TN m-1, respectively. We use our results to assess the validity of the classical view that the mean elevation of an orogenic plateau can be taken as a measure

  16. Using the Mesozoic History of the Canadian Cordillera as a Case Study in Teaching Plate Tectonics.

    ERIC Educational Resources Information Center

    Chamberlain, Valerie Elaine

    1989-01-01

    Reviews a model used in the teaching of plate tectonics which includes processes and concepts related to: terranes and the amalgamation of terranes, relative plate motion and oblique subduction, the effects of continent-continent collision, changes in plate motion, plate configuration, and the type of plate boundary. Diagrams are included.…

  17. ASSEMBLY OF PARALLEL PLATES

    DOEpatents

    Groh, E.F.; Lennox, D.H.

    1963-04-23

    This invention is concerned with a rigid assembly of parallel plates in which keyways are stamped out along the edges of the plates and a self-retaining key is inserted into aligned keyways. Spacers having similar keyways are included between adjacent plates. The entire assembly is locked into a rigid structure by fastening only the outermost plates to the ends of the keys. (AEC)

  18. China's Recruitment of African University Students: Policy Efficacy and Unintended Outcomes

    ERIC Educational Resources Information Center

    Haugen, Heidi Østbø

    2013-01-01

    This article explores how Sino-African relations are affected by the growing number of Africans who pursue higher education in China. China actively recruits African university students in order to increase soft power and generate income from the export of education services. Semi-structured interviews with African university students suggest that…

  19. The African Cultural Astronomy Project

    NASA Astrophysics Data System (ADS)

    Urama, Johnson O.; Holbrook, Jarita C.

    2011-06-01

    Indigenous, endogenous, traditional, or cultural astronomy focuses on the many ways that people and cultures interact with celestial bodies. In most parts of Africa, there is very little or no awareness about modern astronomy. However, like ancient people everywhere, Africans wondered at the sky and struggled to make sense of it. The African Cultural Astronomy Project aims to unearth the body of traditional knowledge of astronomy possessed by peoples of the different ethnic groups in Africa and to consider scientific interpretations when appropriate for cosmogonies and ancient astronomical practices. Regardless of scientific validity, every scientist can relate to the process of making observations and creating theoretical mechanisms for explaining what is observed. Through linking the traditional and the scientific, it is believed that this would be used to create awareness and interest in astronomy in most parts of Africa. This paper discusses the vision, challenges and prospects of the African Cultural Astronomy Project in her quest to popularize astronomy in Africa.

  20. Wellness among African American Counselors

    ERIC Educational Resources Information Center

    Day-Vines, Norma L.; Holcomb-McCoy, Cheryl

    2007-01-01

    Although there are various definitions of wellness, few conceptual definitions have addressed the contextual dimensions of wellness relative to African American counselors. The authors present an overview of generic models of wellness, discuss factors that both inhibit and promote wellness, offer some culture-specific models of wellness, and…

  1. Rotatable shear plate interferometer

    DOEpatents

    Duffus, Richard C.

    1988-01-01

    A rotatable shear plate interferometer comprises a transparent shear plate mounted obliquely in a tubular supporting member at 45.degree. with respect to its horizontal center axis. This tubular supporting member is supported rotatably around its center axis and a collimated laser beam is made incident on the shear plate along this center axis such that defocus in different directions can be easily measured.

  2. Plating Tank Control Software

    1998-03-01

    The Plating Tank Control Software is a graphical user interface that controls and records plating process conditions for plating in high aspect ratio channels that require use of low current and long times. The software is written for a Pentium II PC with an 8 channel data acquisition card, and the necessary shunt resistors for measuring currents in the millampere range.

  3. Genetic position of Andalusians from Huelva in relation to other European and North African populations: a study based on GM and KM allotypes.

    PubMed

    Calderón, R; Ambrosio, B; Guitard, E; González-Martín, A; Aresti, U; Dugoujon, J M

    2006-12-01

    An understanding of population relationships in the Mediterranean region is crucial to the reconstruction of recent human evolution. Andalusia, the most southern region of Spain, has been continuously and densely occupied since ancient times and has a rich history of contacts with many different Mediterranean populations. Thus, to understand the Mediterranean peopling process, investigators should analyze the population relationships between the Iberian peninsula and northern Africa based on an assessment of genetic diversity that takes Andalusia into consideration. The aim of this study was to address the extent of genetic variation in the Iberian peninsula between its geographic extremes (Huelva and the Basque area) and to explain the intensity of the phylogenetic relationships between Andalusians and other neighboring populations, such as those from North Africa. We present, for the first time, results on allotype markers (GM and KM) of human immunoglobulins in the Andalusian population from Huelva. The most frequent GM haplotypes in Andalusia correspond to those that are also the most common in Europe. A sub-Saharan haplotype was found at a relatively high frequency compared to other Iberian samples, and a North Asian marker did not reach polymorphic frequencies in the study sample. A hierarchical cluster analysis based on the first two principal components (94.1% of the total genetic variance) revealed an interesting geographic structure for the 49 populations selected from the literature. The Huelva sample showed a central position in the multivariate space--despite being geographically located at one of the extremes of the Mediterranean basin--and clustered with most Western European populations. Western Europe and Eastern Europe (the latter group paradoxically including Italy and the major islands of the western Mediterranean) were differentiated. North African populations were grouped in two clusters that did not separate either Arabs and Berbers or their

  4. Beyond plate tectonics - Looking at plate deformation with space geodesy

    NASA Technical Reports Server (NTRS)

    Jordan, Thomas H.; Minster, J. Bernard

    1988-01-01

    The requirements that must be met by space-geodetic systems in order to constrain the horizontal secular motions associated with the geological deformation of the earth's surface are explored. It is suggested that in order to improve existing plate-motion models, the tangential components of relative velocities on interplate baselines must be resolved to an accuracy of less than 3 mm/yr. Results indicate that measuring the velocities between crustal blocks to + or - 5 mm/yr on 100-km to 1000-km scales can produce geologically significant constraints on the integrated deformation rates across continental plate-boundary zones such as the western United States.

  5. Informing cancer prevention strategies for African Americans: the relationship of African American acculturation to fruit, vegetable, and fat intake.

    PubMed

    Ard, Jamy D; Skinner, Celette Sugg; Chen, Chuhe; Aickin, Mikel; Svetkey, Laura P

    2005-06-01

    Acculturation has been associated with health-related behaviors in African Americans. We sought to determine if there is a relationship between acculturation and dietary intake in African Americans. African Americans in the PREMIER trial completed the African American Acculturation Scale (AAAS) and 2 nonconsecutive 24-h dietary recalls (n = 238). Analysis of variance (ANOVA) and canonical correlation were used to assess relationships between acculturation and dietary intakes. Canonical correlation (p = 0.05) showed that traditional African Americans had lower intakes of fruits/vegetables and milk/dairy with higher intakes of fats, meat, and nuts. This pattern was supported by differences in the ANOVA. African American acculturation is related to dietary intake. These findings have implications for the design of cancer-related public health messages targeted to African Americans. PMID:16015458

  6. Incorporating Cutting Edge Scientific Results from the Margins-Geoprisms Program into the Undergraduate Curriculum, Rupturing Continental Lithosphere Part II: Introducing Euler Poles Using Baja-North America Relative Plate Motion Across the Gulf of California

    NASA Astrophysics Data System (ADS)

    Loveless, J. P.; Bennett, S. E. K.; Cashman, S. M.; Dorsey, R. J.; Goodliffe, A. M.; Lamb, M. A.

    2014-12-01

    The NSF-MARGINS Program funded a decade of research on continental margin processes. The NSF-GeoPRISMS Mini-lesson Project, funded by NSF-TUES, is designed to integrate the significant findings from the MARGINS program into open-source college-level curriculum. The Gulf of California (GOC) served as the focus site for the Rupturing Continental Lithosphere (RCL) initiative, which addressed several scientific questions: What forces drive rift initiation, localization, propagation and evolution? How does deformation vary in time and space, and why? How does crust evolve, physically and chemically, as rifting proceeds to sea-floor spreading? What is the role of sedimentation and magmatism in continental extension? We developed two weeks of curriculum, including lectures, labs, and in-class activities that can be used as a whole or individually. This component of the curriculum introduces students to the Euler pole description of relative plate motion (RPM) by examining the tectonic interactions of the Baja California microplate and North American plate. The plate boundary varies in rift obliquity along strike, from highly oblique and strike-slip dominated in the south to slightly less oblique and with a larger extensional component in the north. This Google Earth-based exercise provides students with a visualization of RPM using small circle contours of the local direction and magnitude of Baja-North America movement on a spherical Earth. Students use RPM to calculate the fault slip rates on transform, normal, and oblique-slip faults and examine how the varying faulting styles combine to accommodate RPM. MARGINS results are integrated via comparison of rift obliquity with the structural style of rift-related faults around the GOC. We find this exercise to fit naturally into courses about plate tectonics, geophysics, and especially structural geology, given the similarity between Euler pole rotations and stereonet-based rotations of structural data.

  7. Closure of the Africa-Eurasia-North America plate motion circuit and tectonics of the Gloria fault

    NASA Technical Reports Server (NTRS)

    Argus, Donald F.; Gordon, Richard G.; Demets, Charles; Stein, Seth

    1989-01-01

    The current motions of the African, Eurasian, and North American plates are examined. The problems addressed include whether there is resolvable motion of a Spitsbergen microplate, the direction of motion between the African and North American plates, whether the Gloria fault is an active transform fault, and the implications of plate circuit closures for rates of intraplate deformation. Marine geophysical data and magnetic profiles are used to construct a model which predicts about 4 mm/yr slip across the Azores-Gibraltar Ridge, and west-northwest convergence near Gibraltar. The analyzed data are consistent with a rigid plate model with the Gloria fault being a transform fault.

  8. The African Connection

    ERIC Educational Resources Information Center

    Oguntoyinbo, Lekan

    2012-01-01

    From student and faculty exchanges to joint research projects, U.S. universities maintain a broad spectrum of collaborative relationships with African universities. It's unclear how many U.S. colleges and universities have partnerships with African universities. The African Studies Association, an organization of scholars, doesn't keep that kind…

  9. Linguistic Imperialism: African Perspectives.

    ERIC Educational Resources Information Center

    Phillipson, Robert

    1996-01-01

    Responds to an article on aspects of African language policy and discusses the following issues: multilingualism and monolingualism, proposed changes in language policy from the Organization for African Unity and South African initiatives, the language of literature, bilingual education, and whose interests English-language teaching is serving.…

  10. Bathymetry of the Sunda margin, Indonesia: morphological features of the upper plate slopes relate to the location and extent of the seismogenic zone

    NASA Astrophysics Data System (ADS)

    Krabbenhoeft, A.; Weinrebe, W.; Kopp, H.; Flueh, E. R.; Ladage, S.; Papenberg, C. A.; Planert, L.

    2010-12-01

    Earthquake history shows that the Sunda subduction zone of the Indonesian margin produces great earthquakes offshore Sumatra, whereas earthquakes of comparable magnitude are lacking offshore Java and the Lesser Sunda islands. We use morphological structures in multibeam bathymetric data across the forearc to identify the extent of the seismogenic zone (SZ). The updip limit of the SZ is associated with a distinct slope break at the seawordmost part of the outer arc high off Java and the Lesser Sunda islands. In contrast, the slope break is rather indistinctive off large parts of Sumatra. The inner wedge shows differences along the Indonesian margin. Uniform trench-parallel ridge structures lie off Java and Lesser Sunda islands, whereas non-uniform trench-parallel outer arc high structures consisting of several broad tectonic ridges off Sumatra shape the seaward part of the inner wedge. The landward termination of the inner wedge ridge structure and a shallow upper plate mantle at a depth range of ~15-25 km at Java and the Lesser Sunda islands coincide with the downdip limit of the seismogenic zone. In contrast the outer arc ridges off Sumatra are wider and partly elevated above sea level forming the forearc islands. Here, the downdip limit of the seismogenic zone is situated at depths of ~30-40 km, which coincides predominantly with a deeper upper plate mantle. Sunda Strait marks a transition zone between the Sumatra and Java margins. We find the differences along the Sunda margin, especially the wider extent of the seismogenic zone off Sumatra, producing larger earthquakes, to result from the interaction of different age and subduction direction of the oceanic plate. We attribute a major role to the sediment income and continental/island arc upper plate nature of Sumatra/Java influencing the composition and deformation style along the forearc and subduction fault. Off Sumatra the SZ is up to more than twice as wide as off Java and the Sunda islands, enlarging the

  11. A Comparison of Phenotypic Traits Related to Trypanotolerance in Five West African Cattle Breeds Highlights the Value of Shorthorn Taurine Breeds

    PubMed Central

    Berthier, David; Peylhard, Moana; Dayo, Guiguigbaza-Kossigan; Flori, Laurence; Sylla, Souleymane; Bolly, Seydou; Sakande, Hassane; Chantal, Isabelle; Thevenon, Sophie

    2015-01-01

    Background Animal African Trypanosomosis particularly affects cattle and dramatically impairs livestock development in sub-Saharan Africa. African Zebu (AFZ) or European taurine breeds usually die of the disease in the absence of treatment, whereas West African taurine breeds (AFT), considered trypanotolerant, are able to control the pathogenic effects of trypanosomosis. Up to now, only one AFT breed, the longhorn N’Dama (NDA), has been largely studied and is considered as the reference trypanotolerant breed. Shorthorn taurine trypanotolerance has never been properly assessed and compared to NDA and AFZ breeds. Methodology/Principal Findings This study compared the trypanotolerant/susceptible phenotype of five West African local breeds that differ in their demographic history. Thirty-six individuals belonging to the longhorn taurine NDA breed, two shorthorn taurine Lagune (LAG) and Baoulé (BAO) breeds, the Zebu Fulani (ZFU) and the Borgou (BOR), an admixed breed between AFT and AFZ, were infected by Trypanosoma congolense IL1180. All the cattle were genetically characterized using dense SNP markers, and parameters linked to parasitaemia, anaemia and leukocytes were analysed using synthetic variables and mixed models. We showed that LAG, followed by NDA and BAO, displayed the best control of anaemia. ZFU showed the greatest anaemia and the BOR breed had an intermediate value, as expected from its admixed origin. Large differences in leukocyte counts were also observed, with higher leukocytosis for AFT. Nevertheless, no differences in parasitaemia were found, except a tendency to take longer to display detectable parasites in ZFU. Conclusions We demonstrated that LAG and BAO are as trypanotolerant as NDA. This study highlights the value of shorthorn taurine breeds, which display strong local adaptation to trypanosomosis. Thanks to further analyses based on comparisons of the genome or transcriptome of the breeds, these results open up the way for better knowledge

  12. An improved plating process

    NASA Technical Reports Server (NTRS)

    Askew, John C.

    1994-01-01

    An alternative to the immersion process for the electrodeposition of chromium from aqueous solutions on the inside diameter (ID) of long tubes is described. The Vessel Plating Process eliminates the need for deep processing tanks, large volumes of solutions, and associated safety and environmental concerns. Vessel Plating allows the process to be monitored and controlled by computer thus increasing reliability, flexibility and quality. Elimination of the trivalent chromium accumulation normally associated with ID plating is intrinsic to the Vessel Plating Process. The construction and operation of a prototype Vessel Plating Facility with emphasis on materials of construction, engineered and operational safety and a unique system for rinse water recovery are described.

  13. Coupling between plate vibration and acoustic radiation

    NASA Technical Reports Server (NTRS)

    Frendi, Abdelkader; Maestrello, Lucio; Bayliss, Alvin

    1992-01-01

    A detailed numerical investigation of the coupling between the vibration of a flexible plate and the acoustic radiation is performed. The nonlinear Euler equations are used to describe the acoustic fluid while the nonlinear plate equation is used to describe the plate vibration. Linear, nonlinear, and quasi-periodic or chaotic vibrations and the resultant acoustic radiation are analyzed. We find that for the linear plate response, acoustic coupling is negligible. However, for the nonlinear and chaotic responses, acoustic coupling has a significant effect on the vibration level as the loading increases. The radiated pressure from a plate undergoing nonlinear or chaotic vibrations is found to propagate nonlinearly into the far-field. However, the nonlinearity due to wave propagation is much weaker than that due to the plate vibrations. As the acoustic wave propagates into the far-field, the relative difference in level between the fundamental and its harmonics and subharmonics decreases with distance.

  14. Kinematics of the Ethiopian Rift and Absolute motion of Africa and Somalia Plates

    NASA Astrophysics Data System (ADS)

    Muluneh, A. A.; Cuffaro, M.; Doglioni, C.

    2013-12-01

    The Ethiopian Rift (ER), in the northern part of East African Rift System (EARS), forms a boundary zone accommodating differential motion between Africa and Somalia Plates. Its orientation was influenced by the inherited Pan-African collisional system and related lithospheric fabric. We present the kinematics of ER derived from compilation of geodetic velocities, focal mechanism inversions, structural data analysis, and construction of geological profiles. GPS velocity field shows a systematic eastward magnitude increase in NE direction in the central ER. In the same region, incremental extensional strain axes recorded by earthquake focal mechanism and fault slip inversion show ≈N1000E orientation. This deviation between GPS velocity trajectories and orientation of incremental extensional strain is developed due to left lateral transtensional deformation. This interpretation is consistent with the en-échelon pattern of tensional and transtensional faults, the distribution of the volcanic centers, and the asymmetry of the rift itself. Small amount of vertical axis blocks rotation, sinistral strike slip faults and dyke intrusions in the rift accommodate the transtensional deformation. We analyzed the kinematics of ER relative to Deep and Shallow Hot Spot Reference Frames (HSRF). Comparison between the two reference frames shows different kinematics in ER and also Africa and Somalia plate motion both in magnitude and direction. Plate spreading direction in shallow HSRF (i.e. the source of the plumes locates in the asthenosphere) and the trend of ER deviate by about 27°. Shearing and extension across the plate boundary zone contribute both to the style of deformation and overall kinematics in the rift. We conclude that the observed long wavelength kinematics and tectonics are consequences of faster SW ward motion of Africa than Somalia in the shallow HSRF. This reference frame seems more consistent with the geophysical and geological constraints in the Rift. The

  15. Teaching African American Youth: Learning from the Lives of Three African American Social Studies Teachers

    ERIC Educational Resources Information Center

    McBride, Chantee Earl

    2010-01-01

    This study examines the life histories of three African American social studies teachers, focusing on the evolution and changes in their identities, perspectives, and attitudes related to their profession and instructional practice. In addition, the study addresses the significance of the teachers' racialized experiences as African Americans and…

  16. Changing Fatherhood: An Exploratory Qualitative Study with African and African Caribbean Men in England

    ERIC Educational Resources Information Center

    Williams, Robert; Hewison, Alistair; Wildman, Stuart; Roskell, Carolyn

    2013-01-01

    This paper presents findings from a qualitative study undertaken with 46 African and African Caribbean men exploring their experiences of fatherhood. Data analysis was informed by Connell's theoretical work on changing gender relations. Findings indicate that fathers' lives were mediated by masculinities, racism, gender, migration and…

  17. An Ambivalent Community: International African Students in Residence at a South African University

    ERIC Educational Resources Information Center

    Weber, Everard

    2016-01-01

    This is a qualitative case study of the experiences and perceptions of South African and especially international, African students living in university residences in South Africa. The concept, community, is used to interpret interview data. This community was characterised by ambivalent social relations: There was discrimination by South Africans…

  18. Research with African Americans: Lessons Learned about Recruiting African American Women

    ERIC Educational Resources Information Center

    Coker, Angela D.; Huang, Hsin-Hsin; Kashubeck-West, Susan

    2009-01-01

    The authors briefly explore literature related to recruiting African American research participants, reflect on their experiences conducting body image research with a sample of African American college women in an earlier study (S. Kashubeck-West et al., 2008), and discuss some methodological and cultural challenges that they encountered during…

  19. Multicolor printing plate joining

    NASA Technical Reports Server (NTRS)

    Waters, W. J. (Inventor)

    1984-01-01

    An upper plate having ink flow channels and a lower plate having a multicolored pattern are joined. The joining is accomplished without clogging any ink flow paths. A pattern having different colored parts and apertures is formed in a lower plate. Ink flow channels each having respective ink input ports are formed in an upper plate. The ink flow channels are coated with solder mask and the bottom of the upper plate is then coated with solder. The upper and lower plates are pressed together at from 2 to 5 psi and heated to a temperature of from 295 F to 750 F or enough to melt the solder. After the plates have cooled and the pressure is released, the solder mask is removed from the interior passageways by means of a liquid solvent.

  20. 49 CFR 213.123 - Tie plates.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Tie plates. 213.123 Section 213.123 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.123 Tie plates. (a) In Classes 3 through 5...

  1. 49 CFR 213.123 - Tie plates.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Tie plates. 213.123 Section 213.123 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.123 Tie plates. (a) In Classes 3 through 5...

  2. 49 CFR 213.123 - Tie plates.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Tie plates. 213.123 Section 213.123 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.123 Tie plates. (a) In Classes 3 through 5...

  3. 49 CFR 213.123 - Tie plates.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Tie plates. 213.123 Section 213.123 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.123 Tie plates. (a) In Classes 3 through 5...

  4. 49 CFR 236.779 - Plate, top.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Plate, top. 236.779 Section 236.779 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.779 Plate, top....

  5. 49 CFR 236.779 - Plate, top.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Plate, top. 236.779 Section 236.779 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.779 Plate, top....

  6. 49 CFR 236.779 - Plate, top.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Plate, top. 236.779 Section 236.779 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.779 Plate, top....

  7. 49 CFR 236.779 - Plate, top.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Plate, top. 236.779 Section 236.779 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.779 Plate, top....

  8. 49 CFR 236.779 - Plate, top.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Plate, top. 236.779 Section 236.779 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.779 Plate, top....

  9. GPS Constraints on Continental Deformation in the Africa-Arabia-Eurasia Continental Collision Zone and Implications for the Dynamics of Plate Interactions

    NASA Astrophysics Data System (ADS)

    Reilinger, R.; McClusky, S.; Vernant, P.

    2005-12-01

    We present a GPS-derived velocity field (1988-2005) for the zone of interaction of the Arabian, African (Nubian and Somalian), and Eurasian plates. The velocity field indicates counterclockwise rotation of a broad area of the Earth's surface that includes the Arabian plate, adjacent parts of the Zagros and central Iran, Turkey, and the Aegean/Peloponnesus (>7 x 106 km2 5% of the Earth's total surface area) at rates in the range of 20 to 30 mm/yr. This relatively rapid motion occurs within the framework of the slow-moving (<5 mm/yr relative motions) Eurasian, Nubian, and Somalian plates. The circulatory pattern of motion increases in rate towards the Hellenic trench system, suggesting to us that subduction in the eastern Mediterranean is the dominant process responsible for regional deformation. Using seismic and other geophysical and geological information, we develop an elastic block model and use the GPS velocity field to estimate relative block motions. We constrain present-day motions of the Nubian, Somalian, Arabian, and Eurasian plates (relative Euler vectors), regional deformation within the inter-plate zone, and slip rates for major faults. With some important exceptions, geodetic slip rates for major block-bounding structures are comparable to geologic rates estimated for the most recent geological period (3-5 Ma). We find that the convergence of Arabia with Eurasia is accommodated in large part by lateral transport within the interior part of the collision zone and lithospheric shortening along the Caucasus and Zagros mountain belts around the periphery of the collision zone, with little fault-normal convergence within eastern Turkey and the Lesser Caucasus. In addition, we find that the principal boundary between the westerly moving Anatolian plate and Arabia (East Anatolian fault) is presently characterized by pure left-lateral strike slip with no fault-normal convergence and possibly small extension, implying that "extrusion", in the sense of pushing

  10. Evolution of the Malvinas Plate South of Africa

    NASA Astrophysics Data System (ADS)

    Marks, K. M.; Stock, J. M.

    2001-07-01

    We confirm that a Malvinas Plate is required in the Agulhas Basin during the Late Cretaceous because: (1) oblique Mercator plots of marine gravity show that fracture zones generated on the Agulhas rift, as well as the Agulhas Fracture Zone, do not lie on small circles about the 33o-28y South America-Africa stage pole and were therefore not formed by South America-Africa spreading, (2) the 33o-28y South America-Africa stage rotation does not bring 33o magnetic anomalies on the Malvinas Plate into alignment with their conjugates on the African Plate, and (3) errors in the 33o-28y South America-Africa stage rotation cannot account for the misalignment. We present improved Malvinas-Africa finite rotations determined by interpreting magnetic anomaly data in light of fracture zones and extinct spreading rift segments (the Agulhas rift) that are clearly revealed in satellite-derived marine gravity fields covering the Agulhas Basin. The tectonic history of the Malvinas Plate is chronicled through gravity field reconstructions that use the improved Malvinas-Africa finite rotations and more recent South America-Africa and Antarctica-Africa finite rotations. Newly-mapped triple junction traces on the Antarctic, South American, Malvinas, and African Plates, combined with geometric and magnetic constraints observed in the reconstructions, enable us to investigate the locations of the elusive western and southern boundaries of the Malvinas Plate.

  11. Bioenergy and African transformation.

    PubMed

    Lynd, Lee R; Sow, Mariam; Chimphango, Annie Fa; Cortez, Luis Ab; Brito Cruz, Carlos H; Elmissiry, Mosad; Laser, Mark; Mayaki, Ibrahim A; Moraes, Marcia Afd; Nogueira, Luiz Ah; Wolfaardt, Gideon M; Woods, Jeremy; van Zyl, Willem H

    2015-01-01

    Among the world's continents, Africa has the highest incidence of food insecurity and poverty and the highest rates of population growth. Yet Africa also has the most arable land, the lowest crop yields, and by far the most plentiful land resources relative to energy demand. It is thus of interest to examine the potential of expanded modern bioenergy production in Africa. Here we consider bioenergy as an enabler for development, and provide an overview of modern bioenergy technologies with a comment on application in an Africa context. Experience with bioenergy in Africa offers evidence of social benefits and also some important lessons. In Brazil, social development, agricultural development and food security, and bioenergy development have been synergistic rather than antagonistic. Realizing similar success in African countries will require clear vision, good governance, and adaptation of technologies, knowledge, and business models to myriad local circumstances. Strategies for integrated production of food crops, livestock, and bioenergy are potentially attractive and offer an alternative to an agricultural model featuring specialized land use. If done thoughtfully, there is considerable evidence that food security and economic development in Africa can be addressed more effectively with modern bioenergy than without it. Modern bioenergy can be an agent of African transformation, with potential social benefits accruing to multiple sectors and extending well beyond energy supply per se. Potential negative impacts also cut across sectors. Thus, institutionally inclusive multi-sector legislative structures will be more effective at maximizing the social benefits of bioenergy compared to institutionally exclusive, single-sector structures. PMID:25709714

  12. Bioenergy and African transformation.

    PubMed

    Lynd, Lee R; Sow, Mariam; Chimphango, Annie Fa; Cortez, Luis Ab; Brito Cruz, Carlos H; Elmissiry, Mosad; Laser, Mark; Mayaki, Ibrahim A; Moraes, Marcia Afd; Nogueira, Luiz Ah; Wolfaardt, Gideon M; Woods, Jeremy; van Zyl, Willem H

    2015-01-01

    Among the world's continents, Africa has the highest incidence of food insecurity and poverty and the highest rates of population growth. Yet Africa also has the most arable land, the lowest crop yields, and by far the most plentiful land resources relative to energy demand. It is thus of interest to examine the potential of expanded modern bioenergy production in Africa. Here we consider bioenergy as an enabler for development, and provide an overview of modern bioenergy technologies with a comment on application in an Africa context. Experience with bioenergy in Africa offers evidence of social benefits and also some important lessons. In Brazil, social development, agricultural development and food security, and bioenergy development have been synergistic rather than antagonistic. Realizing similar success in African countries will require clear vision, good governance, and adaptation of technologies, knowledge, and business models to myriad local circumstances. Strategies for integrated production of food crops, livestock, and bioenergy are potentially attractive and offer an alternative to an agricultural model featuring specialized land use. If done thoughtfully, there is considerable evidence that food security and economic development in Africa can be addressed more effectively with modern bioenergy than without it. Modern bioenergy can be an agent of African transformation, with potential social benefits accruing to multiple sectors and extending well beyond energy supply per se. Potential negative impacts also cut across sectors. Thus, institutionally inclusive multi-sector legislative structures will be more effective at maximizing the social benefits of bioenergy compared to institutionally exclusive, single-sector structures.

  13. The cardiovascular health of urban African Americans: diet-related results from the Genes, Nutrition, Exercise, Wellness, and Spiritual Growth (GoodNEWS) trial.

    PubMed

    Carson, Jo Ann S; Michalsky, Linda; Latson, Bernadette; Banks, Kamakki; Tong, Liyue; Gimpel, Nora; Lee, Jenny J; Dehaven, Mark J

    2012-11-01

    African Americans have a higher incidence of cardiovascular disease (CVD) than Americans in general and are thus prime targets for efforts to reduce CVD risk. Dietary intake data were obtained from African Americans participating in the Genes, Nutrition, Exercise, Wellness, and Spiritual Growth (GoodNEWS) Trial. The 286 women and 75 men who participated had a mean age of 49 years; 53% had hypertension, 65% had dyslipidemia, and 51% met criteria for metabolic syndrome. Their dietary intakes were compared with American Heart Association and National Heart, Lung, and Blood Institute nutrition parameters to identify areas for improvement to reduce CVD risk in this group of urban church members in Dallas, TX. Results from administration of the Dietary History Questionnaire indicated median daily intakes of 33.6% of energy from total fat, 10.3% of energy from saturated fat, 171 mg cholesterol, 16.3 g dietary fiber, and 2,453 mg sodium. A beneficial median intake of 2.9 cups fruits and vegetables per day was coupled with only 2.7 oz fish/week and an excessive intake of 13 tsp added sugar/day. These data indicate several changes needed to bring the diets of these individuals--and likely many other urban African Americans--in line with national recommendations, including reduction of saturated fat, sodium, and sugar intake, in addition to increased intake of fatty fish and whole grains. The frequent inclusion of vegetables should be encouraged in ways that promote achievement of recommended intakes of energy, fat, fiber, and sodium.

  14. Socioeconomic Status in Relation to the Risk of Ovarian Cancer in African-American Women: A Population-Based Case-Control Study.

    PubMed

    Alberg, Anthony J; Moorman, Patricia G; Crankshaw, Sydnee; Wang, Frances; Bandera, Elisa V; Barnholtz-Sloan, Jill S; Bondy, Melissa; Cartmell, Kathleen B; Cote, Michelle L; Ford, Marvella E; Funkhouser, Ellen; Kelemen, Linda E; Peters, Edward S; Schwartz, Ann G; Sterba, Katherine Regan; Terry, Paul; Wallace, Kristin; Schildkraut, Joellen M

    2016-08-15

    We investigated the association between socioeconomic status and ovarian cancer in African-American women. We used a population-based case-control study design that included case patients with incident ovarian cancer (n = 513) and age- and area-matched control participants (n = 721) from 10 states who were recruited into the African American Cancer Epidemiology Study from December 2010 through December 2014. Questionnaires were administered via telephone, and study participants responded to questions about several characteristics, including years of education, family annual income, and risk factors for ovarian cancer. After adjustment for established ovarian cancer risk factors, women with a college degree or more education had an odds ratio of 0.71 (95% confidence interval (CI): 0.51, 0.99) when compared with those with a high school diploma or less (P for trend = 0.02); women with family annual incomes of $75,000 or more had an odds ratio of 0.74 (95% CI: 0.47, 1.16) when compared with those with incomes less than $10,000 (P for trend = 0.055). When these variables were dichotomized, compared with women with a high school diploma or less, women with more education had an adjusted odds ratio of 0.72 (95% CI: 0.55, 0.93), and compared with women with an income less than $25,000, women with higher incomes had an adjusted odds ratio of 0.86 (95% CI: 0.66, 1.12). These findings suggest that ovarian cancer risk may be inversely associated with socioeconomic status among African-American women and highlight the need for additional evidence to more thoroughly characterize the association between socioeconomic status and ovarian cancer. PMID:27492896

  15. Gene-based analysis of the fibroblast growth factor receptor signaling pathway in relation to breast cancer in African American women: the AMBER consortium.

    PubMed

    Ruiz-Narváez, Edward A; Haddad, Stephen A; Lunetta, Kathryn L; Yao, Song; Bensen, Jeannette T; Sucheston-Campbell, Lara E; Hong, Chi-Chen; Haiman, Christopher A; Olshan, Andrew F; Ambrosone, Christine B; Palmer, Julie R

    2016-01-01

    We conducted gene-based analysis in 26 genes in the FGFR signaling pathway to identify genes carrying genetic variation affecting risk of breast cancer and the specific estrogen receptor (ER) subtypes. Tagging single-nucleotide polymorphisms (SNPs) for each gene were selected and genotyped on a customized Illumina Exome Array. Imputation was carried out using 1000 Genomes haplotypes. The analysis included 3237 SNPs in 3663 breast cancer cases (including 1983 ER-positive, and 1098 ER-negative) and 4687 controls from the African American Breast Cancer Epidemiology and Risk consortium, a collaborative project of four large studies of breast cancer in African American women (Carolina Breast Cancer Study, Black Women's Health Study, Women's Circle of Health Study, and Multiethnic Cohort). We used a multi-locus adaptive joint (AdaJoint) test to determine the association of each gene in the FGFR signaling pathway with overall breast cancer and ER subtypes. The FGF1 gene was significantly associated with risk of ER-negative breast cancer (P = 0.001). The FGFR2 gene was associated with risk of overall breast cancer (P = 0.002) and ER-positive breast cancer (P = 0.002). The FGF1 gene affects risk of ER-negative breast cancer in African American women. We confirmed the association of the FGFR2 gene with risk of overall and ER-positive breast cancer. These results highlight the importance of the FGFR signaling pathway in the pathogenesis of breast cancer, and suggest that different genes in the same pathway may be associated with different ER breast cancer subtypes. PMID:26743380

  16. Hypervelocity plate acceleration

    SciTech Connect

    Marsh, S.P.; Tan, T.H.

    1991-01-01

    Shock tubes have been used to accelerate 1.5-mm-thick stainless steel plates to high velocity while retaining their integrity. The fast shock tubes are 5.1-cm-diameter, 15.2-cm-long cylinders of PBX-9501 explosive containing a 1.1-cm-diameter cylindrical core of low-density polystyrene foam. The plates have been placed directly in contact with one face of the explosive system. Plane-wave detonation was initiated on the opposite face. A Mach disk was formed in the imploding styrofoam core, which provided the impulse required to accelerate the metal plate to high velocity. Parametric studies were made on this system to find the effect of varying plate metal, plate thickness, foam properties, and addition of a barrel. A maximum plate velocity of 9.0 km/s has been observed. 6 refs., 17 figs.

  17. Substance abuse in African American women.

    PubMed

    Wingo, L K

    2001-01-01

    Substance abuse is a serious problem from which, regardless of sex or race, no one is immune. Each racial and gender group has specific etiological factors relating to the use of illicit drugs. Data regarding substance abuse in African American women has only recently begun to emerge in the literature. Issues such as socio-economic, racism, and sexism, place African American women at particular risk for substance abuse. Limited availability to treatment, a lack of appropriate treatment and poor social supports impact recovery and places these women at risk for relapse. This article provides an overview of the current literature regarding substance abuse, treatment and recovery in African American women.

  18. "Half plate of rice to a male casual sexual partner, full plate belongs to the husband": Findings from a qualitative study on sexual behaviour in relation to HIV and AIDS in northern Tanzania

    PubMed Central

    2011-01-01

    developed in close collaboration with affected communities and be closely related to policy-making and implementation; to go beyond the limited success of traditional behavioural and biomedical interventions to particularly address the underlying social and structural drivers of HIV risk and vulnerability in the study communities. PMID:22202562

  19. Plating methods, a survey

    NASA Technical Reports Server (NTRS)

    Berkowitz, J. B.; Emerson, N. H.

    1972-01-01

    Results are presented of a comprehensive search of the literature available, much of which has been generated by the research centers of NASA and its contractors, on plating and coating methods and techniques. Methods covered included: (1) electroplating from aqueous solutions; (2) electroplating from nonaqueous solutions; (3) electroplating from fused-salt baths; (4) electroforming; (5) electroless plating, immersion plating, and mirroring; (6) electroplating from gaseous plasmas; and (7) anodized films and conversion coatings.

  20. GOLD PLATING PROCESS

    DOEpatents

    Seegmiller, R.

    1957-08-01

    An improved bath is reported for plating gold on other metals. The composition of the plating bath is as follows: Gold cyanide from about 15 to about 50 grams, potassium cyanide from about 70 to about 125 grams, and sulfonated castor oil from about 0.1 to about 10 cc. The gold plate produced from this bath is smooth, semi-hard, and nonporous.

  1. PLATES WITH OXIDE INSERTS

    DOEpatents

    West, J.M.; Schumar, J.F.

    1958-06-10

    Planar-type fuel assemblies for nuclear reactors are described, particularly those comprising fuel in the oxide form such as thoria and urania. The fuel assembly consists of a plurality of parallel spaced fuel plate mennbers having their longitudinal side edges attached to two parallel supporting side plates, thereby providing coolant flow channels between the opposite faces of adjacent fuel plates. The fuel plates are comprised of a plurality of longitudinally extending tubular sections connected by web portions, the tubular sections being filled with a plurality of pellets of the fuel material and the pellets being thermally bonded to the inside of the tubular section by lead.

  2. “Culture” in Diabetes-Related Beliefs among Low- and High-Education African American, American Indian, and White Older Adults

    PubMed Central

    Grzywacz, Joseph G.; Arcury, Thomas A.; Ip, Eddie H.; Nguyen, Ha T.; Saldana, Santiago; Reynolds, Teresa; Bell, Ronny A.; Kirk, Julienne K.; Quandt, Sara A.

    2012-01-01

    Objectives Racial and ethnic disparities in diabetes and subsequent complications are often attributed to culture; however, previous diabetes disparities research is restricted to in-depth ethnic-specific samples or to comparative study designs with limited belief assessment. The goal of this study is to improve understanding of the cultural basis for variation in diabetes beliefs. Design Cross-sectional Setting Rural North Carolina Participants Older adults (aged 60+) with diabetes, equally divided by ethnicity (White, African American, American Indian) and gender (N=593). Interventions Guided by Explanatory Models of Illness and Cultural Consensus research traditions, trained interviewers collected data using 38 items in four diabetes belief domains: causes, symptoms, consequences, and medical management. Items were obtained from the Common Sense Model of Diabetes Inventory (CSMDI). Main Outcome Beliefs about diabetes. Response options for each diabetes belief item were “agree,” “disagree” and “don’t know”. Collected data were analyzed using Anthropac (version 4.98) and Latent Gold (version 4.5) programs. Results There is substantial similarity in diabetes beliefs among African Americans, American Indians, and Whites. Diabetes beliefs were most similar in the “symptoms” and “consequences” domains compared to beliefs pertaining to “causes” and “medical management.” Although some discrete beliefs differed by ethnicity, systematic differences by ethnicity were observed for specific educational groups. Conclusions Socioeconomic conditions influence diabetes beliefs rather than “ethnicity” per se. PMID:23140078

  3. INTERFACING INFANT MENTAL HEALTH KNOWLEDGE SYSTEMS: REFLECTIONS ON THE NARRATIVES OF LAY HOME VISITORS' EXPERIENCES OF LEARNING AND APPLYING RELATIONAL CONCEPTS OF DEVELOPMENT IN A SOUTH AFRICAN INTERVENTION PROGRAM.

    PubMed

    Baradon, Tessa; Bain, Katherine

    2016-07-01

    The question of interfacing research and clinically generated knowledge in the field of infant mental health (IMH) with local cultural knowledge and belief systems has provoked extended discussion in recent years. This article explores convergences and divergences between current research-based, relational IMH mental health models and "community" knowledge held by a group of South African lay home visitors from a socioeconomically deprived township. These women were trained in a psychoanalytic and attachment-informed infant mental health program that promotes a relational model of infant development. They provide an intervention that supports high risk mother-infant relationships in the same locality. A two-tiered approach was taken to the analysis of the home visitor interviews and focused on the home visitors' constructed narratives of infant development posttraining as well as the personal impact of the training and work on the home visitors themselves. The study found that psychoanalytic and attachment-informed thinking about development makes sense to those operating within the local South African cultural context, but that the accommodation of this knowledge is a complex and challenging process.

  4. INTERFACING INFANT MENTAL HEALTH KNOWLEDGE SYSTEMS: REFLECTIONS ON THE NARRATIVES OF LAY HOME VISITORS' EXPERIENCES OF LEARNING AND APPLYING RELATIONAL CONCEPTS OF DEVELOPMENT IN A SOUTH AFRICAN INTERVENTION PROGRAM.

    PubMed

    Baradon, Tessa; Bain, Katherine

    2016-07-01

    The question of interfacing research and clinically generated knowledge in the field of infant mental health (IMH) with local cultural knowledge and belief systems has provoked extended discussion in recent years. This article explores convergences and divergences between current research-based, relational IMH mental health models and "community" knowledge held by a group of South African lay home visitors from a socioeconomically deprived township. These women were trained in a psychoanalytic and attachment-informed infant mental health program that promotes a relational model of infant development. They provide an intervention that supports high risk mother-infant relationships in the same locality. A two-tiered approach was taken to the analysis of the home visitor interviews and focused on the home visitors' constructed narratives of infant development posttraining as well as the personal impact of the training and work on the home visitors themselves. The study found that psychoanalytic and attachment-informed thinking about development makes sense to those operating within the local South African cultural context, but that the accommodation of this knowledge is a complex and challenging process. PMID:27186854

  5. African mining

    SciTech Connect

    Not Available

    1987-01-01

    This book contains papers presented at a conference addressing the development of the minerals industry in Africa. Topics covered include: A review - past, present and future - of Zimbabwe's mining industry; Geomorphological processes and related mineralization in Tanzania; and Rock mechanics investigations at Mufulira mine, Zambia.

  6. Earthquakes and plate tectonics

    USGS Publications Warehouse

    Spall, H.

    1977-01-01

    An explanation is to be found in plate tectonics, a concept which has revolutionized thinking in the Earth sciences in the last 10 years. The theory of plate tectonics combines many of the ideas about continental drift (originally proposed in 1912 by Alfred Wegener in Germany) and sea-floor spreading (suggested originally by Harry Hess of Princeton University). 

  7. Blue Willow Story Plates

    ERIC Educational Resources Information Center

    Fontes, Kris

    2009-01-01

    In the December 1997 issue of "SchoolArts" is a lesson titled "Blue Willow Story Plates" by Susan Striker. In this article, the author shares how she used this lesson with her middle-school students many times over the years. Here, she describes a Blue Willow plate painting project that her students made.

  8. Plate-induced Miocene extension in southern California

    SciTech Connect

    Stuart, W.D. Univ. of California, Santa Barbara, CA )

    1992-01-01

    Miocene crustal extension in southern California can be explained by the interaction of tectonic plates in relative motion. The Pacific, Juan de Fuca, and Farallon (Guadalupe) plates are represented by flat elastic plates surrounded by an infinite elastic plate, the eastern part of which represents the North America plate. Forcing is by assigned subduction pull, and tractions at all plate boundaries satisfy a viscous constitutive law. Plate bottoms are stress-free. In the first part of the solution plate velocities and boundary tractions are found from static equilibrium. Then principal horizontal stresses and strains in plate interiors caused by tractions and subduction pull are found by a boundary element procedure. Using plate boundary geometry from Stock and Hodges for early- and mid-Miocene times, it is found that the portion of the North America plate margin between the Mendocino and Rivera triple junctions has maximum extensional strain directed westward. This result is generally consistent with directions associated with metamorphic core complex formation in southern California. The model is also consistent with extensional strain and rotation sense of crustal blocks in the vicinity of Los Angeles, as inferred by Luyendyk and others from paleomagnetic data. In the model the greatest extensional strain of the North America plate occurs near the Pacific-North America transform, in the area above the absent Farallon slab. Extension direction varies from northwest to southwest according to plate geometry, subduction pull (Juan de Fuca and Guadalupe), and plate boundary tractions.

  9. The African superswell

    NASA Technical Reports Server (NTRS)

    Nyblade, Andrew A.; Robinson, Scott W.

    1994-01-01

    Maps of residual bathymetry in the ocean basins around the African continent reveal a broad bathymetric swell in the southeastern Atlantic Ocean with an amplitude of about 500 m. We propose that this region of anomalously shallow bathymetry, together with the contiguous eastern and southern African plateaus, form a superswell which we refer to as the African superswell. The origin of the African superswell is uncertain. However, rifting and volcanism in eastern Africa, as well as heat flow measurements in southern Africa and the southeastern Atlantic Ocean, suggest that the superswell may be attributed, at least in part, to heating of the lithosphere.

  10. Turbine vane plate assembly

    SciTech Connect

    Schiavo Jr., Anthony L.

    2006-01-10

    A turbine vane assembly includes a turbine vane having first and second shrouds with an elongated airfoil extending between. Each end of the airfoil transitions into a shroud at a respective junction. Each of the shrouds has a plurality of cooling passages, and the airfoil has a plurality of cooling passages extending between the first and second shrouds. A substantially flat inner plate and an outer plate are coupled to each of the first and second shrouds so as to form inner and outer plenums. Each inner plenum is defined between at least the junction and the substantially flat inner plate; each outer plenum is defined between at least the substantially flat inner plate and the outer plate. Each inner plenum is in fluid communication with a respective outer plenum through at least one of the cooling passages in the respective shroud.

  11. Pyramidal approach to license plate segmentation

    NASA Astrophysics Data System (ADS)

    Postolache, Alexandru; Trecat, Jacques C.

    1996-07-01

    Car identification is a goal in traffic control, transport planning, travel time measurement, managing parking lot traffic and so on. Most car identification algorithms contain a standalone plate segmentation process followed by a plate contents reading. A pyramidal algorithm for license plate segmentation, looking for textured regions, has been developed on a PC based system running Unix. It can be used directly in applications not requiring real time. When input images are relatively small, real-time performance is in fact accomplished by the algorithm. When using large images, porting the algorithm to special digital signal processors can easily lead to preserving real-time performance. Experimental results, for stationary and moving cars in outdoor scenes, showed high accuracy and high scores in detecting the plate. The algorithm also deals with cases where many character strings are present in the image, and not only the one corresponding to the plate. This is done by the means of a constrained texture regions classification.

  12. GPS constraints on continental deformation in the Africa-Arabia-Eurasia continental collision zone and implications for the dynamics of plate interactions

    NASA Astrophysics Data System (ADS)

    Reilinger, Robert; McClusky, Simon; Vernant, Philippe; Lawrence, Shawn; Ergintav, Semih; Cakmak, Rahsan; Ozener, Haluk; Kadirov, Fakhraddin; Guliev, Ibrahim; Stepanyan, Ruben; Nadariya, Merab; Hahubia, Galaktion; Mahmoud, Salah; Sakr, K.; Arrajehi, Abdullah; Paradissis, Demitris; Al-Aydrus, A.; Prilepin, Mikhail; Guseva, Tamara; Evren, Emre; Dmitrotsa, Andriy; Filikov, S. V.; Gomez, Francisco; Al-Ghazzi, Riad; Karam, Gebran

    2006-05-01

    The GPS-derived velocity field (1988-2005) for the zone of interaction of the Arabian, African (Nubian, Somalian), and Eurasian plates indicates counterclockwise rotation of a broad area of the Earth's surface including the Arabian plate, adjacent parts of the Zagros and central Iran, Turkey, and the Aegean/Peloponnesus relative to Eurasia at rates in the range of 20-30 mm/yr. This relatively rapid motion occurs within the framework of the slow-moving (˜5 mm/yr relative motions) Eurasian, Nubian, and Somalian plates. The circulatory pattern of motion increases in rate toward the Hellenic trench system. We develop an elastic block model to constrain present-day plate motions (relative Euler vectors), regional deformation within the interplate zone, and slip rates for major faults. Substantial areas of continental lithosphere within the region of plate interaction show coherent motion with internal deformations below ˜1-2 mm/yr, including central and eastern Anatolia (Turkey), the southwestern Aegean/Peloponnesus, the Lesser Caucasus, and Central Iran. Geodetic slip rates for major block-bounding structures are mostly comparable to geologic rates estimated for the most recent geological period (˜3-5 Myr). We find that the convergence of Arabia with Eurasia is accommodated in large part by lateral transport within the interior part of the collision zone and lithospheric shortening along the Caucasus and Zagros mountain belts around the periphery of the collision zone. In addition, we find that the principal boundary between the westerly moving Anatolian plate and Arabia (East Anatolian fault) is presently characterized by pure left-lateral strike slip with no fault-normal convergence. This implies that "extrusion" is not presently inducing westward motion of Anatolia. On the basis of the observed kinematics, we hypothesize that deformation in the Africa-Arabia-Eurasia collision zone is driven in large part by rollback of the subducting African lithosphere beneath

  13. Differences between TB cases infected with M. africanum, West-African type 2, relative to Euro-American M. tuberculosis- an update

    PubMed Central

    de Jong, Bouke C; Adetifa, Ifedayo; Walther, Brigitte; Hill, Philip C; Antonio, Martin; Ota, Martin; Adegbola, Richard A

    2009-01-01

    M. africanum is a common cause of human pulmonary TB in West Africa. We previously described phenotypic differences between M. africanum and M. tuberculosis among 290 patients. In the present analysis we compared 692 TB patients infected with the two most common lineages within the M. tuberculosis complex found in the Gambia, namely M. africanum West African type 2 (39% prevalence) and Euro American M. tuberculosis (55% prevalence). We identified additional phenotypic differences between infections with these two organisms. M. africanum patients were more likely to be of older age and HIV infected. In addition, they had worse disease on chest x-ray, despite complaining of cough for equal duration, and were more likely severely malnourished. In this cohort the prevalence of M. africanum did not change significantly over a seven year period. PMID:20002176

  14. Plating To Reinforce Welded Joints

    NASA Technical Reports Server (NTRS)

    Otousa, J. E.

    1982-01-01

    Electrodeposition used to strengthen welded joints gouged, nicked, or suffered other mechanical damage. Plating cell, typically of acrylic plastic such as poly (Methylmetacrylate), is assembled around part to be plated. Areas not to be plated are masked with plater's tape. Weld area is plated in standard nickel-plating process.

  15. Spatial Structure and Climatic Adaptation in African Maize Revealed by Surveying SNP Diversity in Relation to Global Breeding and Landrace Panels

    PubMed Central

    Westengen, Ola T.; Berg, Paul R.; Kent, Matthew P.; Brysting, Anne K.

    2012-01-01

    Background Climate change threatens maize productivity in sub-Saharan Africa. To ensure food security, access to locally adapted genetic resources and varieties is an important adaptation measure. Most of the maize grown in Africa is a genetic mix of varieties introduced at different historic times following the birth of the trans-Atlantic economy, and knowledge about geographic structure and local adaptations is limited. Methodology A panel of 48 accessions of maize representing various introduction routes and sources of historic and recent germplasm introductions in Africa was genotyped with the MaizeSNP50 array. Spatial genetic structure and genetic relationships in the African panel were analysed separately and in the context of a panel of 265 inbred lines representing global breeding material (based on 26,900 SNPs) and a panel of 1127 landraces from the Americas (270 SNPs). Environmental association analysis was used to detect SNPs associated with three climatic variables based on the full 43,963 SNP dataset. Conclusions The genetic structure is consistent between subsets of the data and the markers are well suited for resolving relationships and admixture among the accessions. The African accessions are structured in three clusters reflecting historical and current patterns of gene flow from the New World and within Africa. The Sahelian cluster reflects original introductions of Meso-American landraces via Europe and a modern introduction of temperate breeding material. The Western cluster reflects introduction of Coastal Brazilian landraces, as well as a Northeast-West spread of maize through Arabic trade routes across the continent. The Eastern cluster most strongly reflects gene flow from modern introduced tropical varieties. Controlling for population history in a linear model, we identify 79 SNPs associated with maximum temperature during the growing season. The associations located in genes of known importance for abiotic stress tolerance are

  16. Spiral plate method for bacterial determination.

    PubMed

    Gilchrist, J E; Campbell, J E; Donnelly, C B; Peeler, J T; Delaney, J M

    1973-02-01

    A method is described for determining the number of bacteria in a solution by the use of a machine which deposits a known volume of sample on a rotating agar plate in an ever decreasing amount in the form of an Archimedes spiral. After the sample is incubated, different colony densities are apparent on the surface of the plate. A modified counting grid is described which relates area of the plate of volume of sample. By counting an appropriate area of the plate, the number of bacteria in the sample is estimated. This method was compared to the pour plate procedure with the use of pure and mixed cultures in water and milk. The results did not demonstrate a significant difference in variance between duplicates at the alpha = 0.01 level when concentrations of 600 to 12 x 10(5) bacteria per ml were used, but the spiral plate method gave counts that were higher than counts obtained by the pour plate method. The time and materials required for this method are substantially less than those required for the conventional aerobic pour plate procedure.

  17. Absolute plate velocities from seismic anisotropy: Importance of correlated errors

    NASA Astrophysics Data System (ADS)

    Zheng, Lin; Gordon, Richard G.; Kreemer, Corné

    2014-09-01

    The errors in plate motion azimuths inferred from shear wave splitting beneath any one tectonic plate are shown to be correlated with the errors of other azimuths from the same plate. To account for these correlations, we adopt a two-tier analysis: First, find the pole of rotation and confidence limits for each plate individually. Second, solve for the best fit to these poles while constraining relative plate angular velocities to consistency with the MORVEL relative plate angular velocities. Our preferred set of angular velocities, SKS-MORVEL, is determined from the poles from eight plates weighted proportionally to the root-mean-square velocity of each plate. SKS-MORVEL indicates that eight plates (Amur, Antarctica, Caribbean, Eurasia, Lwandle, Somalia, Sundaland, and Yangtze) have angular velocities that differ insignificantly from zero. The net rotation of the lithosphere is 0.25 ± 0.11° Ma-1 (95% confidence limits) right handed about 57.1°S, 68.6°E. The within-plate dispersion of seismic anisotropy for oceanic lithosphere (σ = 19.2°) differs insignificantly from that for continental lithosphere (σ = 21.6°). The between-plate dispersion, however, is significantly smaller for oceanic lithosphere (σ = 7.4°) than for continental lithosphere (σ = 14.7°). Two of the slowest-moving plates, Antarctica (vRMS = 4 mm a-1, σ = 29°) and Eurasia (vRMS = 3 mm a-1, σ = 33°), have two of the largest within-plate dispersions, which may indicate that a plate must move faster than ≈ 5 mm a-1 to result in seismic anisotropy useful for estimating plate motion. The tendency of observed azimuths on the Arabia plate to be counterclockwise of plate motion may provide information about the direction and amplitude of superposed asthenospheric flow or about anisotropy in the lithospheric mantle.

  18. Active faults, stress field and plate motion along the Indo-Eurasian plate boundary

    NASA Astrophysics Data System (ADS)

    Nakata, Takashi; Otsuki, Kenshiro; Khan, S. H.

    1990-09-01

    The active faults of the Himalayas and neighboring areas are direct indicators of Recent and sub-Recent crustal movements due to continental collision between the Indian and Eurasian plates. The direction of the maximum horizontal shortening or horizontal compressive stress axes deduced from the strike and type of active faulting reveals a characteristic regional stress field along the colliding boundary. The trajectories of the stress axes along the transcurrent faults and the Eastern Himalayan Front, are approximately N-S, parallel to the relative motion of the two plates. However, along the southern margin of the Eurasian plate, they are NE-SW in the Western Himalayan Front and NW-SE to E-W in the Kirthar-Sulaiman Front, which is not consistent with the direction of relative plate motion. A simple model is proposed in order to explain the regional stress pattern. In this model, the tectonic sliver between the transcurrent faults and the plate margin, is dragged northward by the oblique convergence of the Indian plate. Thus, the direction of relative motion between the tectonic sliver and the Indian plate changes regionally, causing local compressive stress fields. Judging from the long-term slip rates along the active faults, the relative motion between the Indian and Eurasian plates absorbed in the colliding zone is about one fourth of its total amount; the rest may be consumed along the extensive strike-slip faults in Tibet and China.

  19. Earthquakes and plate tectonics.

    USGS Publications Warehouse

    Spall, H.

    1982-01-01

    Earthquakes occur at the following three kinds of plate boundary: ocean ridges where the plates are pulled apart, margins where the plates scrape past one another, and margins where one plate is thrust under the other. Thus, we can predict the general regions on the earth's surface where we can expect large earthquakes in the future. We know that each year about 140 earthquakes of magnitude 6 or greater will occur within this area which is 10% of the earth's surface. But on a worldwide basis we cannot say with much accuracy when these events will occur. The reason is that the processes in plate tectonics have been going on for millions of years. Averaged over this interval, plate motions amount to several mm per year. But at any instant in geologic time, for example the year 1982, we do not know, exactly where we are in the worldwide cycle of strain build-up and strain release. Only by monitoring the stress and strain in small areas, for instance, the San Andreas fault, in great detail can we hope to predict when renewed activity in that part of the plate tectonics arena is likely to take place. -from Author

  20. Computational valve plate design

    NASA Astrophysics Data System (ADS)

    Kalbfleisch, Paul

    Axial piston machines are widely used in many industries for their designs compactness, flexibility in power transfer, variable flow rate, and high efficiencies as compared to their manufacturing costs. One important component of all axial piston machines that is a very influential on the performance of the unit is the valve plate. The aim of this research is to develop a design methodology that is general enough to design all types of valve plates and the simple enough not to require advanced technical knowledge from the user. A new style of valve plate designs has been developed that comprehensively considers all previous design techniques and does not require significant changes to the manufacturing processes of valve plates. The design methodology utilizes a previously developed accurate computer model of the physical phenomenon. This allows the precise optimization of the valve plate design through the use of simulations rather than expensive trial and error processes. The design of the valve plate is clarified into the form of an optimization problem. This formulation into an optimization problem has motivated the selection of an optimization algorithm that satisfies the requirements of the design. The proposed design methodology was successfully tested in a case study in the shown to be very successful in improving required performance of the valve plate design.